Chemistry questions and answers

Chemistry Questions and Answers

Learn more about the properties, composition, and structure of substances (elements and compounds) with these Chemistry questions and answers. This Test can be used by students preparing for Chemistry in JAMB, WAEC, NECO or Post UTME.

826.

Which of the following bonds are broken when ethanol is boiled?

I. Covalent bonds
II. Ionic bonds
III. Hydrogen bonds

A.

I only

B.

II only

C.

III only

D.

I, II, III

Correct answer is C

No explanation has been provided for this answer.

827.

Which of the following salts when dissolved in water will form a solution that will change blue litmus to red?

A.

CH3COONa

B.

NH4Cl

C.

NaCl

D.

KCl

Correct answer is B

No explanation has been provided for this answer.

828.

On evaporation to dryness, 3503 of saturated solution of salt Z gave 55.5g of salt. What is the solubility of the salt? [Z = 101]

A.

1.57 moldm-3

B.

3.14 moldm-3

C.

6.28 moldm-3

D.

12.56 moldm-3

Correct answer is A

Saturated solution = 3503
mass of salt Z in saturated solution = 55.5g
Number of moles of salt = \(\frac{55.5}{101}\) = 0.55mole
3503 of solution contains 0.55mole

1000cm3 will contain \(\frac{1000 \times 0.55}{350}\) = 1.57mol/dm3

829.

Which of the following factors will affect the rate of the reaction represented by the following equation?
2HCl(aq) + CaCO3(s) \(\rightarrow\) CaCl2(aq) + H2O(1) + CO2(g)

I. Pressure
II.Concentration
III. Nature of reactants
IV. Temperature

A.

I and II only

B.

II, III and IV only

C.

I, II and III only

D.

I, II. III and IV

Correct answer is B

All others except pressure would affect the equilibrium of the system.

830.

Chemical equilibrium is attained when

A.

All the reactants have been completely used up

B.

The reaction goes to completion

C.

The concentration of reactants and products remain constant

D.

The concentration of reactants and products are equal

Correct answer is C

No explanation has been provided for this answer.