Neco Chemistry 2003 Past Questions and Answers

Question 1:

• 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 2:

• 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 3:

• 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 4:

• 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

Question 5:

• NECO 2003

What mass of silver is deposited when a current of 2.6 A is passed through a solution of a silver salt for 40 minutes? [Ag= 108 ; F=96500C]

A. 6.89g
B. 6.93g
C. 6.98g
D. 7.04g
E. 7.12g