1.
For the reaction
2 NO(g) + O2(g) -->2 NO2(g)
deltaH = -126.0 kJ at 25C.

(a) Calculate the amount of heat transferred when 333 g of NO(g) reacts with O2(g) at 25C and 1 atm.
(b) Does this heat flow into the system or does it flow to the surroundings?
(c) Is this reaction exothermic or endothermic?

2.
If 8675 J of heat flows into 135.0 g of water initially at 20.0C, find the final temperature of
the water. The specific heat of water is 4.18 J g^-1 K^-1.

3.
Find the molecular weight of a gas if 22.24 g of the gas in a 7045 cm^3
container at 20°C exerts a pressure of 698 torr.

CONSTANTS
R = 0.08206 L atm mol^-1 K^-1
1 atm = 760 torr
c = 3.00 x 10^8 m/s
h = 6.63 x 10^-34 J . s

4.
Calculate deltaH at 25C is -1790 kJ for the reaction
C3H6O(l) + 4O2(g) -->3 CO2(g) + 3 H2O(l)

Given these f deltaH values at 25C: -394 kJ/mol for CO2(g), -286 kJ/mol for H2O(l), and 0 for
O2(g), find f deltaH for C3H6O(l).

5.
What volume of H2(g) at 27C and 1.08 atm is produced when
45.3 g of Al reacts as follows:

(a) Calculate the amount of heat transferred when 333 g of NO(g) reacts with O2(g) at 25C and 1 atm.
The molar amount of NO: 333/30.01=11.0963 mol
Heat produced: 126.0/2*11.0963=699.07 kJ

(b) Does this heat flow into the system or does it flow to the surroundings?
Since delta H is negative, it flows to the surroundings.
(c) Is this reaction exothermic or ...

Solution Summary

The great laws and heat of reactions are examined.

... to answer 20 problems dealing with stoichiometry, gas laws, and enthalpy. ... All gases have the same kinetic energy ... 19 According to the first law of thermodynamics ...

Gas Laws and Stoichiometry. ... 1. A gas occupying a volume of 725mL at a pressure of 0.970 atm is allowed to expand at constant temperature ... Boyle's Law says PV = PV ...

... 5. The compound carbon suboxide, C3O2, is a gas at room ... The expert examines calorimetry and Hess' law. ... of a substance is 200gm and its specific heat is 0.09. ...

A problem based on gas laws. A balloon is filled with Helium gas at 20 degrees C and 1.0 atm of pressure. ... What is the heat lost or gained by the helium? ...

LeChatelier's Principle, Equilbrium and Combined Gas Law. ... c) NO2 (g) + O2 (g) + heat ↔ NO (g ... be formed from 30 grams of C4H10 in the following reaction? ...

... of gallium chlorate, 450 grams is heated, to produce ... Therefore, the heat capacity per mole of many metals is ... a volatile liquid using the ideal gas law (PV = nRT ...

... If the gas is in a container that can contract or ... Solution The above problem is based on Charles law, as pressure ... g) to form NaF(s), 13.8 kJ of heat is evolved ...

... the reaction releases heat, delta H (+) or heat is absorb ... 2. Using Pressure law, we have: P1 P2 = T1 T2 ... 3. Using combined gas laws, we have: P1V1 P2V2 = T1 T2 ...