Question 796:

• JAMB 1993

The standard enthalpies of formation of CO_2(g), H₂O(g) and CO_(g) in kJ mol^- are -394, -242 and -110 respectively. What is the standard enthalpy change for the reaction CO_(g) + H_2(g)O → CO_2(g) + H_2(g)?

A. -42 KJ mol^-
B. +42 KJ mol^-
C. -262 KJ mol^-
D. +262 KJ mol^-

Question 797:

• JAMB 1993

10g of a solid is in equilibrium with its own vapour.
When 1 g of a small amount of solid is added, the vapour pressure?

A. Remains the same
B. Drops
C. Increases by 1%
D. Increases by 99%

Question 798:

• JAMB 1993

NaCI_(s) + H₂SO_4(I) → HCI_(g) + NaHSO_4(s).
In the reaction above, H₂SO₄ behaves as?

A. A strong acid
B. An oxidizing agent
C. A good solvent
D. A dehydrating agent

Question 799:

• JAMB 1993

Which of these gases can be dried with concentrated H2SO4?

A. HBr
B. H₂S
C. NH₃
D. SO₂

Question 800:

• JAMB 1993

Which of these salts will produce its metal, oxygen and nitrogen (IV) oxide on heating?

A. Silver and trioxonitrate (V)
B. Sodium trioxonitrate (V)
C. Calcium trioxonitrate (V)
D. Lithium trioxonitrate (V)