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Unofficial practice · EUEE

2018 E.C. Chemistry EUEE past paper

67 questions · 2018 E.C. / 2026 G.C. · Natural stream · unofficial

Unofficial practice for the 2018 E.C. / 2026 G.C. Chemistry Ethiopian University Entrance Exam (EUEE / matric). 67 question stems from the Abrari bank are listed below. Not an official Ministry, EAES, MoLS, or OCACC paper.

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Unofficial EUEE past-paper items. Not an official key.

1 / 5chemistryPolymers / step-growth

Which one is a step-growth polymer?

Unofficial practice. Abrari is an independent study aid and is not affiliated with, endorsed by, or an official product of the Ethiopian Ministry of Education (MoE), EAES, MoLS, or OCACC. Answers are Abrari keys, not an official marking scheme.

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Stems are visible for study. Worked solutions stay inside each item and are unofficial.

Q1 · Polymers / step-growth

Which one is a step-growth polymer?
  1. A. Polyester
  2. B. PTFE
  3. C. Polystyrene
  4. D. PVC
Worked solutionUnofficial

Unofficial keyed letter A. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q2 · Polymers / thermoplastics

All of the following are thermoplastic polymers; except:
  1. A. Polyethylene
  2. B. Nylon
  3. C. Bakelite
  4. D. Dacron
Worked solutionUnofficial

Unofficial keyed letter C. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q3 · Polymers / addition polymers

All of the following are addition polymer; except:
  1. A. Dacron
  2. B. PVC
  3. C. Polypropylene
  4. D. PMMA
Worked solutionUnofficial

Unofficial keyed letter A. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q4 · Polymers / trade names

Which polymer is sold under the trade name Lucite or Plexiglas?
  1. A. PTFE
  2. B. PET
  3. C. PMMA
  4. D. Nylon-66
Worked solutionUnofficial

Unofficial keyed letter C. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q5 · Polymers / uses

Which one is the use of Teflon?
  1. A. It is used as airplane windows.
  2. B. It is used for making pipes and raincoats.
  3. C. It is used for making parachutes and ropes.
  4. D. It is used for coating cooking utensils.
Worked solutionUnofficial

Unofficial keyed letter D. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q6 · Polymers / monomers

The widely used PVC is a polymerized product of ______
  1. A. CH2=CH2\mathrm{CH_2{=}CH_2}
  2. B. CH2=CCl2\mathrm{CH_2{=}CCl_2}
  3. C. CH2Cl−CH2Cl\mathrm{CH_2Cl{-}CH_2Cl}
  4. D. CH2=CHCl\mathrm{CH_2{=}CHCl}
Worked solutionUnofficial

Unofficial keyed letter D. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q7 · Organic chemistry / esterification

The compound CH3CH2CH2CH2CH2OH\mathrm{CH_3CH_2CH_2CH_2CH_2OH} and CH3−CH2−CH2−CH2COOH\mathrm{CH_3{-}CH_2{-}CH_2{-}CH_2COOH} react in the presence of an acid catalyst to form ____________
  1. A. carboxylic acid
  2. B. alcohol
  3. C. ester
  4. D. aldehyde
Worked solutionUnofficial

Unofficial keyed letter C. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q8 · Hydrocarbons / reactivity

Which one of the following classes of hydrocarbon is less reactive?
  1. A. Alkane
  2. B. Alkene
  3. C. Alkyne
  4. D. Aromatic hydrocarbon
Worked solutionUnofficial

Unofficial keyed letter A. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q9 · Alcohols / oxidation

Alcohol that yield aldehyde on oxidation are classified as
  1. A. secondary alcohol
  2. B. primary alcohol
  3. C. dihydric alcohol
  4. D. trihydric alcohol
Worked solutionUnofficial

Unofficial keyed letter B. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q10 · Metallurgy / ore concentration

During concentrating the ore; which method is chemical method?
  1. A. Leaching
  2. B. Froth floatation
  3. C. Amalgamation
  4. D. Gravity separation
Worked solutionUnofficial

Unofficial keyed letter A. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q11 · Metallurgy / roasting

Roasting is generally done in case of the:
  1. A. oxide ores
  2. B. silicate ores
  3. C. sulphide ores
  4. D. carbonate ores
Worked solutionUnofficial

Unofficial keyed letter C. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q12 · Metallurgy / gold and silver extraction

Extraction of gold and silver involves leaching with CN−\mathrm{CN^-} ion. Silver is later recovered by:
  1. A. distillation
  2. B. zone refining
  3. C. liquation
  4. D. displacement with Zn
Worked solutionUnofficial

Unofficial keyed letter D. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q13 · Industrial chemistry / catalysts

What type of catalyst is used in the contact process?
  1. A. V2O5\mathrm{V_2O_5}
  2. B. Fe
  3. C. Ni
  4. D. Pt
Worked solutionUnofficial

Unofficial keyed letter A. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q14 · Industrial chemistry / tanning

In the tanning process, the purpose of putting the skin into slaked lime solution is to:
  1. A. Facilitate the removal of unwanted flesh
  2. B. Facilitate the removal of hair
  3. C. Dehydrate the skin
  4. D. Soften the skin
Worked solutionUnofficial

Unofficial keyed letter B. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q15 · Polymers / condensation polymers

Nylon-66 is obtained by condensation polymerization of
  1. A. Adipic acid and hexamethylene diamine
  2. B. Terephthalic acid and ethylene glycol
  3. C. Phenol and formaldehyde
  4. D. Acrylic acid and ethane diol
Worked solutionUnofficial

Unofficial keyed letter A. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q16 · Metallurgy / aluminium extraction

What is the purpose of adding cryolite during the extraction of aluminum from bauxite in the Hall process?
  1. A. To get pure aluminum oxide
  2. B. To dissolve impurities like iron oxides
  3. C. To lower the melting point of crude bauxite
  4. D. To decrease the conductivity of bauxite
Worked solutionUnofficial

Unofficial keyed letter C. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q17 · Salts / deliquescence

Salts that absorb water from the atmosphere and become solution are:
  1. A. deliquescent
  2. B. efflorescent
  3. C. hygroscopic
  4. D. Florescent
Worked solutionUnofficial

Unofficial keyed letter A. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q18 · Qualitative analysis / anion tests

If a salt releases a reddish – brown gas upon heating with a disagreeable smell that turns moist blue litmus into red, which anion is most likely present in the salt?
  1. A. Bromide
  2. B. Nitrate
  3. C. Sulphate
  4. D. Carbonate
Worked solutionUnofficial

Unofficial keyed letter B. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q19 · Polymers / molar mass

What is the molar mass of a polyethylene sample [−CH2−CH2−]n\mathrm{[-CH_2{-}CH_2-]_n}, when n = 4600? (H = 1, C = 12)
  1. A. 1.288×1031.288 \times 10^{3} g/mol
  2. B. 1.196×1041.196 \times 10^{4} g/mol
  3. C. 1.196×1031.196 \times 10^{3} g/mol
  4. D. 1.288×1051.288 \times 10^{5} g/mol
Worked solutionUnofficial

Unofficial keyed letter D. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q20 · Quantum numbers

Which of the following quantum number is not permitted in sub-level notation?
  1. A. n=2, ℓ=0n = 2,\ \ell = 0
  2. B. n=3, ℓ=3n = 3,\ \ell = 3
  3. C. n=4, ℓ=3n = 4,\ \ell = 3
  4. D. n=1, ℓ=0n = 1,\ \ell = 0
Worked solutionUnofficial

Unofficial keyed letter B. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q21 · Salt hydrolysis

Which salt yields a basic solution on dissolution in water?
  1. A. Salts of strong acid & strong base
  2. B. Salts of weak acid & strong base
  3. C. Salts of weak base & strong acid
  4. D. Salts of NaOH and HCl
Worked solutionUnofficial

Unofficial keyed letter B. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q22 · Buffer solutions

Which pair of compounds forms a buffer solution?
  1. A. KCl/HCl\mathrm{KCl/HCl}
  2. B. CH3COONa/H2SO4\mathrm{CH_3COONa/H_2SO_4}
  3. C. NaNO3/HNO3\mathrm{NaNO_3/HNO_3}
  4. D. NH4Cl/NH3\mathrm{NH_4Cl/NH_3}
Worked solutionUnofficial

Unofficial keyed letter D. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q23 · Salt hydrolysis / cation hydrolysis

Which one of the following undergoes cation hydrolysis?
  1. A. BaI2\mathrm{BaI_2}
  2. B. NaNO3\mathrm{NaNO_3}
  3. C. MgSO4\mathrm{MgSO_4}
  4. D. CH3COONa\mathrm{CH_3COONa}
Worked solutionUnofficial

Unofficial keyed letter C. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q24 · Electromagnetic radiation

Which of the following devices is designed to produce electromagnetic radiation with the longest wavelength in order to operate?
  1. A. Light bulb
  2. B. Microwave oven
  3. C. X-ray microscope
  4. D. FM radio transmitter
Worked solutionUnofficial

Unofficial keyed letter D. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q25 · Periodic table / transition elements

Which group of elements have variable valence and make colored compound?
  1. A. Transition elements
  2. B. Representative elements
  3. C. Rare earth metals
  4. D. P – block elements
Worked solutionUnofficial

Unofficial keyed letter A. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q26 · Redox / oxidation number

When Cr2(SO4)3\mathrm{Cr_2(SO_4)_3} changed to CrO3\mathrm{CrO_3}; the oxidation number of Chromium:
  1. A. Decrease as it undergo reduction
  2. B. Increase as it undergo reduction
  3. C. Increase as it undergo oxidation
  4. D. Decrease as it undergo oxidation
Worked solutionUnofficial

Unofficial keyed letter C. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q27 · Quantum numbers / electron capacity

What is the maximum number of electrons in n=5, mℓ=−1n = 5,\ m_\ell = -1?
  1. A. 6e
  2. B. 12 e
  3. C. 8 e
  4. D. 32e
Worked solutionUnofficial

Unofficial keyed letter C. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q28 · Redox / oxidation number

What is the oxidation number of "Cr" in the ionic compound ammonium dichromate, (NH4)2Cr2O7\mathrm{(NH_4)_2Cr_2O_7}?
  1. A. +3
  2. B. +7
  3. C. +6
  4. D. +5
Worked solutionUnofficial

Unofficial keyed letter C. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q29 · Electrochemistry / corrosion

A metal corrodes if;
  1. A. It serve as cathode in the corrosion process
  2. B. It does not react with oxygen
  3. C. It serve as anode in the corrosion process
  4. D. It is plated with corrosion resistant metal
Worked solutionUnofficial

Unofficial keyed letter C. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q30 · Electrochemistry / cell potential

What is E° for the following balanced reaction? Use the information given below.

4H+(aq)+Fe(s)+NO3−(aq)→Fe3+(aq)+NO(aq)+2H2O(l)\mathrm{4H^+(aq) + Fe(s) + NO_3^-(aq) \rightarrow Fe^{3+}(aq) + NO(aq) + 2H_2O(l)}

I. NO3−+4H++3e−→NO+2H2O\mathrm{NO_3^- + 4H^+ + 3e^- \rightarrow NO + 2H_2O} Ered∘=+0.960E^\circ_{red} = +0.960 V

II. Fe3++3e−→Fe\mathrm{Fe^{3+} + 3e^- \rightarrow Fe} Ered∘=−0.771E^\circ_{red} = -0.771 V
  1. A. +0.189 V
  2. B. –0.189 V
  3. C. –1.731 V
  4. D. +1.731 V
Worked solutionUnofficial

Unofficial keyed letter D. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q31 · Salt hydrolysis / pH

The pH of an aqueous sodium fluoride (NaF) solution is _____ because _____
  1. A. 7; Sodium fluoride is a neutral salt.
  2. B. Above 7; Fluoride ion is a strong base.
  3. C. Below 7; fluoride reacts with water to make hydrofluoric acid
  4. D. Above 7; fluoride ion is a weak base
Worked solutionUnofficial

Unofficial keyed letter D. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q32 · Electrolysis / products

The substance formed at the anode during the electrolysis of dilute sodium chloride is:
  1. A. Hydrogen
  2. B. Chlorine
  3. C. Sodium
  4. D. Oxygen
Worked solutionUnofficial

Unofficial keyed letter D. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q33 · Acid-base equilibrium / Ka

The percentage dissociation of a 0.20 M formic acid is 3.2%. What is its dissociation constant?
  1. A. 2.1×10−22.1 \times 10^{-2}
  2. B. 9.6×10−89.6 \times 10^{-8}
  3. C. 2.1×10−42.1 \times 10^{-4}
  4. D. 1.1×10−61.1 \times 10^{-6}
Worked solutionUnofficial

Unofficial keyed letter C. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q34 · Redox / oxidizing agent

The following reaction occurs in basic solution. Identify the oxidizing agent. Note the reaction equation is not balanced. H2O(l)+Zn(s)+NO3−(aq)+OH−(aq)→Zn(OH)42−(aq)+NH3(aq)\mathrm{H_2O(l) + Zn(s) + NO_3^-(aq) + OH^-(aq) \rightarrow Zn(OH)_4^{2-}(aq) + NH_3(aq)}
  1. A. Zn(s)\mathrm{Zn(s)}
  2. B. NO3−(aq)\mathrm{NO_3^-(aq)} (the nitrogen)
  3. C. H2O(l)\mathrm{H_2O(l)} (the oxygen)
  4. D. NH3(aq)\mathrm{NH_3(aq)} (the nitrogen)
Worked solutionUnofficial

Unofficial keyed letter B. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q35 · Electrochemistry / Nernst equation

In the electrochemical reaction: 2Fe3++Zn→Zn2++2Fe2+\mathrm{2Fe^{3+} + Zn \rightarrow Zn^{2+} + 2Fe^{2+}}, on increasing the concentration of Fe2+\mathrm{Fe^{2+}}
  1. A. increases cell emf
  2. B. decreases the cell emf
  3. C. increases the current flow
  4. D. alters the pH of the solution
Worked solutionUnofficial

Unofficial keyed letter B. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q36 · Electrochemistry / electrolytic vs voltaic cells

One of the differences between a voltaic cell and an electrolytic cell is that in an electrolytic cell ___
  1. A. Electron's flow toward the anode
  2. B. A non-spontaneous reaction is forced to occur
  3. C. An electric current is produced by a chemical reaction
  4. D. O2\mathrm{O_2} gas is produced at the cathode
Worked solutionUnofficial

Unofficial keyed letter B. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q37 · Electrolytes / conductivity

The highest electrical conductivity of the following aqueous solutions is of
  1. A. 0.1 M Sugar
  2. B. 0.1 M MgCl2\mathrm{MgCl_2}
  3. C. 0.1 M AlCl3\mathrm{AlCl_3}
  4. D. 0.1 M Ca3N2\mathrm{Ca_3N_2}
Worked solutionUnofficial

Unofficial keyed letter D. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q38 · Electrolysis / Faraday's law

In a solution of CuSO4\mathrm{CuSO_4} how much time will be required to precipitate 2 g copper by 0.5 ampere current?
  1. A. 12157.48 sec
  2. B. 102 sec
  3. C. 510 sec
  4. D. 642 sec
Worked solutionUnofficial

Unofficial keyed letter A. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q39 · Activity series

Based on the periodic table and general patterns of activity, which of the following would react with metallic calcium? (KBr\mathrm{KBr}, NaI\mathrm{NaI}, FeCl2\mathrm{FeCl_2}, NiBr2\mathrm{NiBr_2})
  1. A. KBr\mathrm{KBr} and NaI\mathrm{NaI} only
  2. B. Both FeCl2\mathrm{FeCl_2} and NiBr2\mathrm{NiBr_2}
  3. C. FeCl2\mathrm{FeCl_2} only
  4. D. NiBr2\mathrm{NiBr_2} only
Worked solutionUnofficial

Unofficial keyed letter B. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q40 · Industrial chemistry / Haber process

Ammonia is manufactured in industry according to the following reaction: N2+3H2→2NH3\mathrm{N_2 + 3H_2 \rightarrow 2NH_3}. Which one of the following is TRUE about currently used sources of the reactants?
  1. A. Both nitrogen and hydrogen are obtained directly from air.
  2. B. Both nitrogen and hydrogen are obtained as petroleum products.
  3. C. Nitrogen is obtained from thermal decomposition of nitrates while hydrogen is from methane from natural gas.
  4. D. Nitrogen is obtained from fractional distillation of liquid air while hydrogen is from the electrolytic decomposition of water.
Worked solutionUnofficial

Unofficial keyed letter D. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q41 · Bohr model / orbit radius

The radius of the second orbit of hydrogen is 2.12 Å. The radius of the first orbit would be:
  1. A. 0.53 Å
  2. B. 0.26 Å
  3. C. 1.06 Å
  4. D. 0.12 Å
Worked solutionUnofficial

Unofficial keyed letter A. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q42 · Electromagnetic radiation / photon energy

What is the quantum energy associated with the sodium-D line having a wavelength of 589 nm?
  1. A. 3.38×10−193.38 \times 10^{-19} J
  2. B. 5.4×10−195.4 \times 10^{-19} J
  3. C. 2.7×10−192.7 \times 10^{-19} J
  4. D. 4.56×10−194.56 \times 10^{-19} J
Worked solutionUnofficial

Unofficial keyed letter A. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q43 · Quantum numbers

Which sets of quantum number (n,ℓ,mℓ,ms)(n, \ell, m_\ell, m_s) is not permitted by the rules of quantum Mechanics respectively?
  1. A. 1, 0, 0, +½
  2. B. 3, 2, -1, -½
  3. C. 4, 3, 2, -½
  4. D. 2, 2, 1, +½
Worked solutionUnofficial

Unofficial keyed letter D. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q44 · Electron configuration / subshell capacity

Maximum number of electrons in a subshell of an atom is determined by:
  1. A. 4ℓ+24\ell + 2
  2. B. 2n22n^2
  3. C. n2n^2
  4. D. 2ℓ+12\ell + 1
Worked solutionUnofficial

Unofficial keyed letter A. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q46 · Molecular orbital theory

What is the bond order and magnetic property respectively of F2+\mathrm{F_2^+}?
  1. A. 1.5, paramagnetic
  2. B. 2.5, diamagnetic
  3. C. 2.0, diamagnetic
  4. D. 0.5, paramagnetic
Worked solutionUnofficial

Unofficial keyed letter A. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q47 · Periodic table / diagonal relationship

The chemistry of lithium is very similar to that of magnesium even though they are placed in different groups. Its reason is:
  1. A. Both are found together in nature
  2. B. Both have nearly the same size
  3. C. Both have similar electronic configuration
  4. D. The ratio of their charge and size (i.e. charge density) is nearly the same
Worked solutionUnofficial

Unofficial keyed letter D. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q48 · Periodic table / groups

Which pair of elements belongs to same group?
  1. A. Elements with atomic no. 17 and 38
  2. B. Elements with atomic no. 20 and 40
  3. C. Elements with atomic no. 17 and 53
  4. D. Elements with atomic no. 11 and 33
Worked solutionUnofficial

Unofficial keyed letter C. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q49 · Hydrogen spectrum

The wavelength of which series lie towards the ultraviolet?
  1. A. Lyman
  2. B. Balmer
  3. C. Paschen
  4. D. Bracket
Worked solutionUnofficial

Unofficial keyed letter A. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q50 · Chemical bonding / sigma and pi bonds

How many sigma & pi bond are there in CH3−CN\mathrm{CH_3{-}CN} molecule respectively?
  1. A. 4σ & 2π
  2. B. 3σ & 2π
  3. C. 4σ & 3π
  4. D. 5σ & 2π
Worked solutionUnofficial

Unofficial keyed letter D. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q51 · Molecular polarity

Which of the following four molecules is/are polar: PH3\mathrm{PH_3}, OF2\mathrm{OF_2}, HF\mathrm{HF}, SO3\mathrm{SO_3}?
  1. A. Only HF\mathrm{HF} and SO3\mathrm{SO_3}
  2. B. Only HF\mathrm{HF}
  3. C. Only HF\mathrm{HF} and OF2\mathrm{OF_2}
  4. D. PH3\mathrm{PH_3}, OF2\mathrm{OF_2} and HF\mathrm{HF}
Worked solutionUnofficial

Unofficial keyed letter D. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q52 · Hybridization

What is the hybridization of the central atom in the BCl3\mathrm{BCl_3} molecule?
  1. A. sp
  2. B. sp²
  3. C. sp³
  4. D. sp³d¹
Worked solutionUnofficial

Unofficial keyed letter B. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q53 · VSEPR / bond angles

What are the bond angles in NO3−\mathrm{NO_3^-}?
  1. A. 90º
  2. B. 109.5º
  3. C. 120º
  4. D. 90º and 120º
Worked solutionUnofficial

Unofficial keyed letter C. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q54 · Hybridization

What is the hybridization of the carbon atoms in ethyne, C2H2\mathrm{C_2H_2}?
  1. A. sp²
  2. B. sp³d
  3. C. sp³
  4. D. sp
Worked solutionUnofficial

Unofficial keyed letter D. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q55 · Hybridization

The hybridization associated with the central atom of a molecule in which all the bond angles are 120° is:
  1. A. sp
  2. B. sp²
  3. C. sp³
  4. D. sp³d
Worked solutionUnofficial

Unofficial keyed letter B. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q56 · Hybridization

The central atom in a molecule has three regions of high electron density. What type of hybrid orbitals are formed by the central atom?
  1. A. sp²
  2. B. sp³d
  3. C. sp³
  4. D. sp³d²
Worked solutionUnofficial

Unofficial keyed letter A. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q57 · VSEPR / molecular shape

Which of the following species has a linear shape?
  1. A. I3−\mathrm{I_3^-}
  2. B. SO2\mathrm{SO_2}
  3. C. O3\mathrm{O_3}
  4. D. ClO2\mathrm{ClO_2}
Worked solutionUnofficial

Unofficial keyed letter A. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q58 · Solids / network covalent

Silicon dioxide (SiO2\mathrm{SiO_2}) and diamonds are best described as
  1. A. molecular substances with coordinate covalent bonding
  2. B. molecular substances with ionic bonding
  3. C. network solids with covalent bonding
  4. D. network solids with ionic bonding
Worked solutionUnofficial

Unofficial keyed letter C. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q59 · VSEPR / bond angles

Which molecular structure will have the bond angle of 120° around the central atom?
  1. A. Triangular planar
  2. B. Seesaw
  3. C. Triangular bipyramid
  4. D. Octahedral
Worked solutionUnofficial

Unofficial keyed letter A. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q60 · VSEPR / molecular shape

A molecule with five bonding pair and one lone pair electron has
  1. A. octahedral shape
  2. B. trigonal bipyramid shape
  3. C. square pyramid shape
  4. D. tetrahedral shape
Worked solutionUnofficial

Unofficial keyed letter C. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q61 · VSEPR / bond angles

The bond angle in H2O\mathrm{H_2O} is
  1. A. = BeCl2\mathrm{BeCl_2}
  2. B. < NH4+\mathrm{NH_4^+}
  3. C. > CO2\mathrm{CO_2}
  4. D. > BF3\mathrm{BF_3}
Worked solutionUnofficial

Unofficial keyed letter B. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q62 · Chemical equilibrium

Which of the following is true regarding the concentration of products, for a chemical reaction that is already at equilibrium, assuming no disruptions to the equilibrium?
  1. A. The concentrations of products will not change because there are no more reactants.
  2. B. The concentrations of products will not change because the limiting reagent is gone.
  3. C. The [ ] of products will not change because the forward and reverse rates are equal.
  4. D. The concentrations of products will change continually because of reversibility.
Worked solutionUnofficial

Unofficial keyed letter C. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q63 · Chemical equilibrium / equilibrium constant

For the chemical equilibrium A+2B⇌2C\mathrm{A + 2B \rightleftharpoons 2C}, the value of the equilibrium constant, KCK_C, is 16. What is the value of the equilibrium constant for the following reaction? 12A+B⇌C\mathrm{\tfrac{1}{2}A + B \rightleftharpoons C}, KC=?K_C = ?
  1. A. 4.0
  2. B. 0.20
  3. C. 40
  4. D. 400
Worked solutionUnofficial

Unofficial keyed letter A. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q64 · Chemical equilibrium / Le Chatelier

For the reaction N2O4⇌2NO2\mathrm{N_2O_4 \rightleftharpoons 2NO_2}; ΔH = +14 kJ. The extent of the reaction can be increased by:
  1. A. Increasing the pressure
  2. B. Using a catalyst
  3. C. Increasing the temperature
  4. D. Introduce inert gas at constant volume
Worked solutionUnofficial

Unofficial keyed letter C. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q65 · Chemical equilibrium / magnitude of K

In which of the following cases the reaction goes farthest to completion?
  1. A. Kc=10−2K_c = 10^{-2}
  2. B. Kc=103K_c = 10^{3}
  3. C. Kc=102K_c = 10^{2}
  4. D. Kc=10−3K_c = 10^{-3}
Worked solutionUnofficial

Unofficial keyed letter B. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q66 · Gases / ideal gas

Which of the following statements is true about an ideal gas? It is a hypothetical gas that obeys the gas laws
  1. A. at low temperature and low pressure
  2. B. at low temperature and high pressure
  3. C. closely at high temperatures and low pressures
  4. D. closely at high temperatures and high pressures
Worked solutionUnofficial

Unofficial keyed letter C. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q67 · Graham's law of diffusion

If an unknown gas diffuses 1.75 times faster than sulfur dioxide gas, what is the molar mass of the unknown gas? (molar mass of "SO2\mathrm{SO_2}" is 64)
  1. A. 21.16
  2. B. 36.57
  3. C. 48
  4. D. 96
Worked solutionUnofficial

Unofficial keyed letter A. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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Q68 · States of matter / phase change

During a phase change, the temperature of a substance
  1. A. increases.
  2. B. stays the same.
  3. C. decreases.
  4. D. Unknown
Worked solutionUnofficial

Unofficial keyed letter B. A full worked solution is not published for this item yet.

Unofficial — solved by Abrari, not an official EAES key.

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