Chemistry MCQs

Chemistry MCQs

Answer these 200+ Chemistry MCQs and assess your grip on the subject of Chemistry. Scroll below and get started!

1: A sample of 502 has volume 2.45 L at a pressure of 4.6 x103 Pa. What he new volume of the gas, if the pressure is changed to 1.4 x104 Pa and the temperature is kept constant?

A.   0.81 L

B.   0.57 L

C.   1.12 L

D.   1.34 L

2: At 298 K and 1 atmospheric pressure, a given mass of gas occupies the 30 mL volume. If the pressure is increased to 1.50 atmosphere and the temperature is kept constant. then what is the volume of the gas?

A.   25 mL

B.   18 mL

C.   24 mL

D.   20 mL

3: If the volume of a sample of a gas at 15°C and 1 aim is 3.12 L. then what is the volume of this gas at 42"C and 1 atm?

A.   3.15 L

B.   2.82 L

C.   3.41 L

D.   2.12 L

4: If the partial pressure of oxygen in air is 184 torr and the total atmospheric pressure is 782 torr, then what is the mole fraction of 02 present?

A.   0.413

B.   1.217

C.   1.387

D.   0.235

5: Which of the following options is the correct bond length of CC (Alkanes) bond?

A.   1.00 A

B.   0.68 A

C.   1.54 A

D.   1.76 A

6: Which of the following options is the correct bond energy of C—Br bond?

A.   55.0 Kcallmole

B.   69.0 Kcallmole

C.   74.0 Kcallmole

D.   81.0 Kcallmole

7: What is the correct atomic radii (pm) of hydrogen (H)?

A.   8

B.   12

C.   24

D.   32

8: A solution is prepared by dissolving 11.5 g of solid NaOH in enough water for making 1.40 L of the solution. What is the molarity of this solution?

A.   0.112 M NaOH

B.   0-243 M NaOH

C.   0.206 M NaOH

D.   0.184 M NaOH

9: How many protons are dissociated by polyprotic acids at a time?

A.   One

B.   Two

C.   Three

D.   Four

10: Which of the following options is the correct Ka value of the oxyacid HCIO2?

A.   1.2 )(10-2

B.   3.5 x10-8

C.   2.4 x 10-4

D.   5.1 :«10-3

11: What is the correct value of the pH of 1.0 X 10‘10 M HCl?

A.   1.00

B.   5.00

C.   7.00

D.   9.00

12:

It is given that:

TC = 190.55 K

pC = 4.604 MPa

VC = 99 cm3 mol

A.  

360 kg m‘3

B.  

227 kg m'3

C.  

440 kg m'3

D.  

400 kg m‘3

13: Which of the following options is the correct value of the molecular mass of hydrated copper sulphate (CuSoa . SHZO)?

A.   240

B.   245

C.   250

D.   255

14:

Complete the given chemical reaction.

2BaS + 2H20 »


A.  

2BaO + 2H2S 

B.  

Ba(SH)2 + Ba(OH)2 

C.  

Ba2O + 2H2S

D.  

8as2 + BaOH + H20

15:

Complete the given chemical reaction.

Fe3O4 + 8HC| » 7?


A.  

2FeCI3 + FeCl2 + 4H20

B.  

3Fec12 + 4H20 + Cl2

C.  

2FeCI + 2FeCI2 + 4H20 + c12

D.  

2FeCl3 + FeCl2 + 4H20

16: On heating 0.197 gm of an organic substance with excess of strong nitric acid and silver nitrate gives 3.525 gm of silver iodide. What will be the percentage of iodine in this compound?

A.   43.71%

B.   51.84%

C.   36.68%

D.   31.53%

17: In relation to the oxidation-reduction process, which of the following statements is NOT correct about an oxidized element?

A.   It loses electrons.

B.   Its oxidization state decreases.

C.   It acts as reducing agent.

18: Which of the following chemical reactions takes place between silver nitrate and the solution of neutral tartrate?

A.   C4H4O6 + 2AQ’ " A92C4H406

B.   C4H4O6 + 2Ag+ » AgC4H4O4 + 2A902

C.   C4H406 + 2Ag+ -> 2AgO + c.11404

D.   C4H406 + 2Ag+ -» A92C2H402 +2co2

19: While dissolving 0.3 mol NH3 (g) in 54.045 9 H20 (l) at 25°C and pressure 101.325 kPa, it was found that a heat of 6870 J passed to the surroundings. Calculate the correct value of me].

A.   8

B.   10

C.   12

D.   15

20: With regard to the radioactive processes, what is the effect of positron production on neutron/proton ratio?

A.   The neutron/proton ratio increases.

B.   The neutron/proton ratio decreases.

C.   It does not affect the neutron/proton ratio.

21: If k is the rate constant, T is the absolute temperature in kelvin, A is the pre—exponential factor, E0 is the activation energy and R is the universal gas constant, then which of the following options is correct according to Arrhenius' equation?

A.   k = Ae‘Ea’an

B.   k= AEaeR/T

C.   kEa: eN(RT)

D.   kEa ___ eART

22: Which of the following options dissolved in chloroform is used as a nitrating agent in the organic synthesis?

A.   N2O5

B.   NCL3

C.   N2O4

D.   NF3

23: What is the life of the uranium nuclide in the decay of Uranium — 234 (atomic number — 92) which decays to Thorium ~230 (atomic number — 90) and produces an a particle?

A.   2.48 x105 years

B.   8 x104 years

C.   4.51 x109 years

D.   3.28 days

E.   24.1 days

24: It is given that the mass of an article is 150 Q. What is the mass of the article in ounces?

A.   6.74 oz

B.   3.17oz

C.   5.29 oz

D.   7.16 oz

25: In relation to acid-base properties of salts, which of the following options results in the production of basic solutions?

A.   Cations of strong bases and anions of strong acids.

B.   Cations of weak bases and anions of strong acids.

C.   Cations of strong bases and anions of weak acids.

D.   Cations of weak bases and anions of weak acids.

26: During which of the following types of chemical reactions, an insoluble substance, such as a solid is formed and is separated from the solution on mixing of the two solutions?

A.   Acid-base reactions

B.   Oxidation-reduction reactions

C.   Precipitation reactions

D.   None of the above.

27: lfV is the volume of gas, n is the number of moles of gas particles and a is a proportionality constant, then which of the following options correctly states the Avogadro's law?

A.   a/V = n

B.   V = an

C.   n = aV

D.   Vn = a

28: Which of the following laws of chemistry states that the partial vapor pressure of each component of an ideal mixture of liquids is equal to the pure component's vapor pressure multiplied with its mole fraction?

A.   Newlands' law of octaves

B.   Law of mass action

C.   Raoult's law

D.   Periodic law

29: In relation to the ion-selective electrodes, which of the following options is used as a reference solution?

A.   Dilute hydrochloric acid

B.   Dilute sulphuric acid

C.   Dilute carbonic acid

D.   Dilute acetic acid

30: Which of the following chemical equations correctly represents the reaction that takes place when phosphonium iodide is heated at 60°C?

A.   PH4I—PH2» PHZ + H2!

B.   2PH4I > 2PH3 + H2I2

C.   PH4I .. PH3 + Hi

D.   2PH4I» P2H6 + 2Hl

31: What is the standard reduction potential for the given reaction at 25°C? H202 (aq) + 2H1”) + 2e’-> 2H20 (I)

A.   +1.23 E° / v

B.   +2.87 E° / v

C.   +0.45 E° [V

D.   +1.77 E° /v

32: Which of the following chemical reactions correctly illustrates the heating of iron disulphate (FeSQ) at 600°C in a vacuum?

A.   Fes2 4 Fe + 52

B.   2Fes2 4 FeZS + s

C.   Fes2 4 FeS + s

D.   2Fes2 4 Fe2S4

33: In relation to the base strength in aqueous solutions, which of the following options has the highest base strength?

A.   CN'

B.   H20

C.   OH’

34: Complete the given chemical reaction. Cuso4 + 2Kl 4

A.   CuK2 + I2SO4..

B.   Col2 + K2SO4

C.   CuKzlz + SO2 + 02

D.   Cul202 + 2KSO2

35: For the production of10.5 g of silver metal. how long must a current of 6.5 A should be applied to the Ag' solution?

A.   26.8 min

B.   24.1 min

C.   31.2 min

D.   22.7 min

36:

Which of the following lithium compounds has the given characteristics?

- It decomposes at 380°C.

- It reacts water.

- It consists of white orthorhombic crystals.


A.  

Lithium amide

B.  

Lithium borohydride

C.  

Lithium bromide

D.  

Lithium carbonate

37: The stirring rod is made of which of the following material?

A.   Metal

B.   Wood

C.   Glass

D.   Plastic

38: Which of the following options is the correct wavelength range of infrared radiations?

A.   3 x10“2 to 7 x10'5 cm

B.   1.8 x10'3 to 6 x10'6 cm

C.   4 x10‘2 to 8 x10'7 cm

D.   2x10-2to 9x104 cm

39: What is the percent dissociation of an acetic acid (KB =18 x10‘5) in 0.100 M HC2H3O2 solution?

A.   0.8%

B.   1.3%

C.   1.6%

D.   2%

40: In relation to corrosion, which of the following chemical reaction equations is correct?

A.   2Fe2+ (aq) +02 (9) + (4 + 2n)H20 (I) 4 F9203 . nHZO (s) + 4H+ (aq)

B.   4Fe2+ (aq) +02 (9) + (4 + 2n)H20 (1)» 2Fe203 . nHQO (s) + 8H+ (aq)

C.   4Fe2+ (aq) +02 (9) + (4 + 2n)l-I20 (l) -* 2Fe20 . nH20 (s) + 8H+ (aq) + 2FeO (aq)

D.   2Fe2+ (aq) +02 (9) + (4 + 2n)H20 (I) + 2Fe03 . nl-IZO (s) + 4H° (aq)

41:

In relation to ammonium chloride, complete the given chemical reaction.

2NH4C| + CuC12 -v


A.  

2NH4 + CuCI4

B.  

Nzl-l4 + 2I-ICI +CuCl4

C.  

(NH4)2 + CuCl4

D.  

2NH4 + Cl2 + CuCl2

42: Which of the following laws of chemistry states that the mole fraction of a gas dissolved in a solvent is directly proportional to the partial pressure of the gas?

A.   Raoult's Law

B.   Henry's law

C.   Lavoisier-Laplace law

D.   Hess law

43: If the half-life of molybdenum-99 is 67.0 h, then how much of a 1.000-mg sample of Mo (atomic weight = 99 and atomic number = 42) is left after 335 h?

A.   0.18 mg

B.   0.081 mg

C.   0.32 mg

D.   0.031 mg

44: What is the correct molecular formula of an organic compound that has the molecular weight of 90 and the empirical formula CHZO? It is given that, C =12, H =1, and 0 =16.

A.   C6H12O6

B.   C3H6O3

C.   CzH4O6

D.   C2H8O4

45: At a temperature of100°C and at a pressure of 27.6 MP8, the volume Occupied by two moles of carbon dioxide is 140.06 cm3. What will be the compressibility factor?

A.   0.7821

B.   0.6230

C.   0.8442

D.   0.6588

46: What is the correct elemental composition of Chromium Chloride?

A.   Cr is 32.84%, Cl is 67.16%

B.   Cr is 38.62%, Cl is 61.38%

C.   Cr is 27.22%. Cl is 72.78%

D.   Cr is 45.35%, CI is 54.68%

47: Which of the following statements is not correct about heat?

A.   In an endothermic process, energy as heat flows into a system.

B.   The f‌low of energy is due to a temperature difference.

C.   It is a state function.

D.   In an exothermic process. energy as heat flows out of a system.

48: Which of the following statements is not correct about the kinetic molecular theory of gases?

A.   The volume of gas particles is zero.

B.   The average kinetic energy of the particles of gas is inversely proportional to the gas temperature (temperature in kelvins).

C.   There is no interaction among the gas particles.

D.   The gas particles are in constant motion which collide with the container walls and produces pressure.

49: Which of the following laws of chemistry states that the molar volume of different gases at the same temperature and pressure has the same value?

A.   Gay-Lussac’s law

B.   Boyle's law

C.   Avogadro’s law

D.   None of the above.

50: In relation to Charles' law, what is the effect of decreasing the absolute temperature of the gas on its volume?

A.   The volume will decrease.

B.   The volume will increase.

C.   It will have no effect on the volume.