Question

30)
a)how much heat is released(in kJ) when 100.0 g H2O(l) is formed from the combustion of H2(g) and O2(g)
2H2(g) + 2O2(g) →2H2O(l) ∆H°=-571.6 kJ.
b) in an exothermic reaction? a) heat is absorbed from the surroundings b) temperature is constant c) pressure increases d) heat is transferred to the surroundings
c) which of the following does not require a heat transfer into the system? a)bond formation b) vaporization c) sublimation d) all require heat in

D) doubling the volume of an ideal gas at constant temperature will? a) double the pressure b) reduce the pressure by half c) have no effect d) double the temperature

Answer 1

2H2(g) + 2O2(g) → 2H2O(l)    ∆H°=-571.6 kJ.

a) 36 grams of water produces ------------> -571.6 KJ

100 grams of water produces ----------> -571.6*100/36 = -1587.78 KJ.

b) in an exothermic reaction?

Answer = d) heat is transferred to the surroundings

c) which of the following does not require a heat transfer into the system?

Answer = a)bond formation

d) doubling the volume of an ideal gas at constant temperature will?

Answer = b) reduce the pressure by half.