1)Which one of the following statements about all exothermic reactions is true?
A. There is a net input of energy from the surroundings.
B. The enthalpy of the products is greater than the enthalpy of the reactants.
C. The energy required to break the bonds of the reactants is less than the energy released when the products are formed.
D. The energy required to break the bonds of the reactants is greater than the energy released when the products are formed.

Solution

2) Oscar calibrated a solution calorimeter by passing a current of 2.50 A through a heater with a voltage of 12.0 V for 150 s. He measured the temperature of the water, which increased from
22.3 °C to 28.4 °C. The calibration factor (CF) of the calorimeter was
A. 16.1 J °C^-1
B. 158 J °C^-1
C. 202 J °C^-1
D. 738 J °C^-1

Solution

3) The molar enthalpy for combustion of glucose, C₆H₁₂O₆, is
−2840 kJ mol^-1 . Which one of the following describes what occurs to one mole of carbon dioxide, CO₂, during photosynthesis?
A. 473.3 kJ of energy is absorbed.
B. 2840 kJ of energy is absorbed.
C. 473.3 kJ of energy is released.
D. 2840 kJ of energy is released.

Solution