Processing math: 100%

WAEC Chemistry Past Questions & Answers - Page 81

401.

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]

1.57 moldm^-3

3.14 moldm^-3

6.28 moldm^-3

12.56 moldm^-3

View answer & explanation

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

402.

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

I and II only

II, III and IV only

I, II and III only

I, II. III and IV

View answer & explanation

Correct answer is B

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

403.

The refreshing characteristic taste of fizzy drinks is due ot the presence of

Carbon(IV)oxide

Glucose

Hydrogen

Sodium Citrate

View answer & explanation

Correct answer is A

No explanation has been provided for this answer.

404.

Consider the following reaction equation
H₃O⁺_(aq) + OH_(aq) $\rightarrow$ 2H₂O₍₁₎
The reaction represents

Esterification

Hydrolysis

Neutralization

Redox

View answer & explanation

Correct answer is C

No explanation has been provided for this answer.

405.

The pH of four solutions M,N,Q and R are 2,6,8 and 11 respectively.
Which of the following deductions about the solutions is correct?

The pH of N is increased when the solution is diluted

The pH of Q is increased when the solution is evaporated

M is the most alkaline solution

R is the most acidic solution

View answer & explanation

Correct answer is A

No explanation has been provided for this answer.

WAEC Subjects

Literature in English

Islamic Religious Knowledge

Christian Religious Knowledge

Aptitude Tests

Quantitative Reasoning Questions and Answers

Puzzles Questions and Answers

Abstract Reasoning Questions and Answers

Personality Test

Microsoft Office Questions and Answers

Nigeria General Knowledge Questions and Answers

Numerical Reasoning Questions and Answers

Logical Reasoning Questions and Answers

Verbal Reasoning Questions and Answers

Typing Speed and Accuracy Test

Data Interpretation Questions and Answers

Situational Judgement Questions and Answers

Spatial Reasoning Questions and Answers

See all →

View latest jobs in Nigeria today