Waec Chemistry 2011 Past Questions and Answers

Question 51:

• WAEC 2011

(a)(i) What is a functional group?
(ii) State the functional group in each of the following compounds: I. CH${}_3$CH${}_2$CH(CH${}_3$)OH; II. CH${}_3$CH${}_2$CH${}_2$COOH.

(b)(i) Complete the following equations:

(ii) Draw the structure(s) of the product(s) formed in (b)(i) above.

(c)(i).Write an equation for the prepzration of butan-2-ol from butene.

(d) (i) Give the reagents required for the following conversions to take place: I. CH${}_2$ = CH${}_2$ to CH${}_3$CH${}_2$OH; II. CH${}_3$CH${}_2$OH to CH${}_3$COOH; Ill. CH${}_3$COOH to CH${}_3$COOCH${}_2$CH${}_3$.

(e) Consider the following organic structure; CH${}_3$OHCHCH = CHCOOH
(i) State what would be observed when the organic compound is treated with each of the following reagents: I. cold NaHCO${}_{3(aq)}$; II. hot solution of I${}_2$ in NaOH${}_{(aq)}$; Ill. bromine water.

Question 52:

• WAEC 2011

(a) A compound X reacts with excess HNO${}_{3(aq)}$ to give carbon (IV) oxide and another compound Y. A solution of Y reacts with NaOH${}_{(aq)}$ to form a white precipitate which is insoluble in excess NaOH${}_{(aq)}$. Identify X and Y.
(b) (i) Write a balanced equation to illustrate the reducing property of ammonia in its reaction with CuO.
(ii) Explain why it is not advisable to heat ammonium dioxonitrate (III) directly.
(iii) Give two uses nitrogen.
(c) Give the reason why (i) dilute H${}_2$SO${}_4$ is not suitable for the preparation of CO${}_{2(g)}$ from CaCO${}_{3(s)}$ (ii) concentrated H${}_2$SO${}_4$ cannot be used to dry ammonia gas.
(d) State two: (i) physical properties; (ii) chemical properties of metals.
(e) What is the oxidation number of: (i) chlorine in I. Cl${}_2$. II. ClO${}_{-(3)}$
(ii) vanadium in V${}_2$O${}_5$
(f)(i) Explain the term half-life. (ii) Two radioactive elements, P and Q have half-life of 1200 seconds and 3600 seconds respectively.
I. Which of the elements is more stable? II. Give a reason for your answer.