Neco Chemistry Past Questions and Answers

Question 61:

• NECO 2003

Small amounts of compounds of transition metals are sometimes added to glass during manufacture in order to make the glass

A. Acquire certain colours
B. Easier to melt
C. Easier to mould
D. Little brittle
E. More transparent

Question 62:

• NECO 2003

The pH of water is 7.

What is the pH of orange juice?

A. 7
B. Above 10
C. Below 2
D. Between 5.5 and 6.5
E. Between 7.5 and 8.5

Question 63:

• NECO 2003

Chlorine displaces bromine from aqueous potassium bromide because ____________

A. Bromine is a liquid at room temperature
B. Bromine is weakly acidic.
C. Bromine has a greater atomic radius than chlorine
D. Chlorine is a stronger oxidising agent than bromine.
E. The density of chlorine is less than the density of bromine.

Question 64:

• NECO 2003

What is the change in the oxidation number of phosphorus in the following reaction?

4P(s) + 5O₂(ag) → 2P₂O₅(s)

A. 0 to 2
B. 0 to 5
C. 4 to 2
D. 4 to 5
E. 4 to 10

Question 65:

• NECO 2003

In the reaction 2H₂S(g) + SO₂(g) → 2H₂SO(I)+3S(s)SO₂is acting as ____________ agent

A. A bleaching
B. A dehydrating
C. An oxidizing
D. A precipitating
E. A reducing