Energy changes - Jamb Chemistry Past Questions and Answers

Question 26:

• JAMB 1990

X(g) → X\(^-\)(g). The type of energy involved in the above transformation is?

A. Ionization energy
B. Sublimation energy
C. Lattice energy
D. Electron affinity

Question 27:

• JAMB 1991

In two separate experiments, 0.36g and 0.71g of chlorine combined with a metal X to give Y and Z respectively. An analysis showed that Y and Z contain 0.20g and 0.40g of X respectively. The data above represents the law of ?

A. Multiple proportion
B. Conservation of mass
C. Constant composition
D. Reciprocal proportion

Question 28:

• JAMB 1991

30cm\(^3\) of oxygen at 10 atmospheres pressure is placed in a 20 cm\(^3\) container. Calculate the new pressure if temperature is kept constant?

A. 6.7 atm
B. 15.0 atm
C. 60.0 atm
D. 66. 0 atm

Question 29:

• JAMB 1991

1.1 g of CaCI2 dissolved in 50 cm3 of water caused a rise in temperature of3.4°C. The heat of reaction, ∆H for CaCI2 in kj per mole is?
(Ca = 40, CI = 35.5, specific heat of water is 4.18 jk-1

A. -71.1
B. -4.18
C. +71.1
D. +111.0

Question 30:

• JAMB 1992

In which of the following is the entropy change positive?

A. H₂O_(I) → H₂O_(g)
B. Cu²⁺_{(aq) + Fe[sub](s)} → Fe⁽²⁺⁾ + Cu_(s)[/sub]
C. N_2(g) + 3H_2(g) → 2NH_3(g)
D. 2HCI_(s) → H_2(g) + CI_2(g)