Question 541:

• JAMB 1988

Which of the followingstatements is TRUE?

A. The dissolution of NaOH_(s) in water is endothermic
B. The heat os solution of NaOH_(s) is positive
C. The NaOH_(s) gains heat from the surroundings
D. The heat of solution of NaOH_(s) is negative

Question 542:

• JAMB 1988

Which property of a reversible reaction is affected by a catalyst?

A. Heat content (enthalphy)
B. Energy of activation
C. Free energy change
D. Equilibrium position

Question 543:

• JAMB 1988

Which of the following is used in fire extinguishers?

A. Carbon (ll) oxide
B. Carbon (lV) oxide
C. Sulphur (lV) oxide
D. Ammonia

Question 544:

• JAMB 1988

When H₂S gas is passed into a solution of iron (III) chloride, the colour changes from yellow to green. This is because?

A. H_(s)S is reduced to S
B. Fe³⁺ ions are oxidized by H_(s)S
C. Fe³⁺ ions are oxidized Fe³⁺ ions
D. Fe³⁺ ions are reduced to Fe²⁺ ions

Question 545:

• JAMB 1988

Suitable reagents for the laboratory preparation nitrogen are?

A. Sodium dioxonitrate (III) and ammonium chloride
B. Sodium dioxonitrate (V) and ammonium chloride
C. Sodium chloride and ammonium chloride
D. Sodium chloride and ammonium diozonitrate (III)