Neco Chemistry 2003 Past Questions and Answers

Question 21:

• 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 22:

• 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 23:

• 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 24:

• 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

Question 25:

• NECO 2003

What is the number of moles of NaHCO₃in 250cm³ of its solution if the solution contains 8.4 g of NaHCO₃ in 1 dm³ of the solution. [Na = 23, 0 = 16, C = 12, H = 1)

A. 1
B. 0.25
C. 0.05
D. 0.025
E. 0.01