Neco Chemistry Past Questions and Answers

Question 41:

• NECO 2001

Which of the following is TRUE of a catalyst? I. it alters the activation energy of a reaction
II. it is effective in a reaction but cannot initiate a reaction
III, it affects the equilibrium of a reversible reaction
IV. it affects the overall reaction

A. I and II only
B. I, II and III only
C. II and III only
D. II, II and IV only
E. III and IV only

Question 42:

• NECO 2003

What mass of copper is deposited when 6.5g of granulated zinc reacts with excess copper(II) tetraoxosulphate(VI) solution?

The equation for the reaction is: Zn(s) + \( CuSO_4(aq)→ ZnSO_4(aq)+ Cu(s)\)[CU= 64; Zn=65]

A. 3.2 g
B. 3.25 g
C. 6.4 g
D. 6.5 g
E. 64.0 g

Question 43:

• NECO 2003

An organic compound gave the following results on analysis: C = 29.3% ; H = 5.7%; Br = 65%.
What is the empirical formula of the compound? [C = 12, H = 1, Br=80]

A. CH₃Br
B. C₂H₅Br
C. C₃H₅Br
D. C₃H₇Br
E. C₄H₉Br

Question 44:

• NECO 2003

Why does the treatment of cotton fabrics with dilute acids weaken the materials?

A. Cotton is hydrolysed completely to glucose
B. The fabrics are soluble in dilute acids
C. The molecular chains are partially broken
D. The molecular chain length f the fabric increases
E. The thread holding the fabric together Is completely destroyed.

Question 45:

• NECO 2003

Naturally occurring lithium consists of 90% \( ^7_3Li \text{ and 10% } ^6_3 Li. \) What is the relative atomic mass of lithium?

A. 6
B. 6.8
C. 6.9
D. 7
E. 7.1