Chemistry 2011 Waec Past Questions and Answers

Question 31 :

• WAEC 2011

Which of the following metallic oxides is amphoteric?

A. AI₂O₃
B. Fe₂O₃
C. MgO
D. Na₂O

Question 32 :

• WAEC 2011

On evaporation to dryness, 250 cm³ of saturated solution of salt X with relative molar mass 101 gave 50.5g of the. What is the soluility of the salt?

A. 1.0 mol dm^-3
B. 20 mol dm^-3
C. 4.0 moldm^-3
D. 5.0 moldm^-3

Question 33 :

• WAEC 2011

Consider the following reaction equation: X_(g)
+ Y_(g) ⇌ XY_(g); ∆H = + 220KJ mol^-1 If the temperature of the system is increased, the

A. Backward reaction would be favoured
B. Forward reaction would favoured
C. Reaction would stop
D. Reaction would be at equilibrium

Question 34 :

• WAEC 2011

What is the value of n in the following equation? Cr₂O₇^2- + 14H⁺ + ne^- → 2Cr ³⁺ + 7H₂O

A. 2
B. 3
C. 6
D. 7

Question 35 :

• WAEC 2011

What mass of copper would be formed when a current of 10.0 A is passed through a solution of CuSO₄ for 1 hour? [Cu = 63.5; 1F = 96500C]

A. 5.9 g
B. 11.8 g
C. 23.8 g
D. 47.3 g