Neco Chemistry Past Questions and Answers

Question 51:

• NECO 2003

How many Faradays of electricity are required to liberate 9g of aluminium? [Al = 27]

A. 0.1
B. 0.3
C. 1
D. 2.7
E. 3

Question 52:

• NECO 2003

At s.t.p, a mole of chlorine occupies 22.4dm³. If the temperature is changed to 35°C and the pressure to 750mHg the of the new volume will be [Cl = 35.5]

A. \( ^{\text{760 x 22.4 x 308}} \text{750 x 273x 35.5} dm^3 \)
B. \( ^{\text{760 x 22.4 x 308}} \text{750 x 273}^x dm^3 \)
C. \( ^{\text{750 x 22.4 x 35.5}} \text{760 x 273dm3} \)
D. \( ^{\text{760 x 22.4 x 35.5}} \text{750x22.3x273} \)
E. \( ^{\text{760 x 22.4 x 35.5}} \text{750 x 308dm3} \)

Question 53:

• NECO 2003

What is the concentration (in mol dm³) of a solution containing 28 g of potassium hydroxide per 100 cm³ of solution? (K=39; H=1; 0=16)

A. 0.01
B. 0.05
C. 0.1
D. 0.5
E. 2.8

Question 54:

• NECO 2003

Which method is used for the purification of copper from its ore?

A. Distillation
B. Electrochemical
C. Electrolysis
D. Neutralization
E. Reduction

Question 55:

• NECO 2003

Ethene decolourises acidified potassium tetraoxomanganate(VII) solution. Which gas will decolourise bromine water?

A. CH₄
B. C₂H₆
C. C₃H₆
D. C₃H₈
E. C₆H₆