641. The process of exchanging heat in a chemical reaction under constant pressure and temperature is known as:
A. Entropy change
B. Enthalpy change
C. Internal energy change
D. Free energy change
642. Water has a molar heat capacity of 75 JK-1 mol-1 at constant pressure, or cp. When 1.0 kJ of intensity is provided to 100 g of water, which is allowed to extend, the expansion in temperature of water is:
A. 6.6 K
B. 1.2 K
C. 2.4 K
D. 4.8 K
643. What is the entropy change ( in JK-1 MOL-1) when one mole of ice is changed over into water at 0 degrees Celsius? (At 0 degrees Celsius, the enthalpy change required to transform ice into liquid water is 6.0 kJ mol-1.)
A. 21.98
B. 20.13
C. 2.013
D. 2.198
644. When a system transitions from state A to state B, the internal energy change is 40 kJ/mole. What would be the total change in internal energy if the system traveled from state A to state B in a reversible manner and then returned to state A in an irreversible manner?
A. 40 kJ
B. > 40 kJ
C. < 40 kJ
D. Zero
645. Enthalpy of formation of HF and HCl are -161 kJ and -92 kJ respectively. Which of the following statements is incorrect?
A. Fluorine has a greater affinity for hydrogen than chlorine does for hydrogen.
B. HF is more stable than HCl
C. HCl is more stable than HF
D. HF and HCl are endothermic compounds
646. Which of the following is not an organic compound?
a) Methane
b) Carbon dioxide
c) Ethanol
d) Benzene
647. The general formula of alkanes is:
a) CnH2n+2
b) CnH2n
c) CnH2n-2
d) CnH2n-4
648. What is the name of the compound CH3-CH2-CH2-CH3?
a) Methane
b) Ethane
c) Propane
d) Butane
649. Which functional group is present in alcohols?
a) -OH (hydroxyl)
b) -COOH (carboxyl)
c) -NH2 (amino)
d) -CHO (aldehyde)
650. The process of converting alkenes into alkanes by adding hydrogen is called:
a) Hydrogenation
b) Polymerization
c) Saponification
d) Substitution
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