Heat capacity
Steel has a specific heat capacity of 0.45 J/g°C. The temperature of the steel increases from 300°C to 460°C, and the heat absorbed by the steel is 5600 J. Calculate the mass of the steel.
77.78 g
What is the formula for Delta H rxn?
Delta H products - Delta H reactants
A gas has a volume of 800.0 mL at −23.0 °C and 300.0 torr. What would the volume of the gas be at 227.0 °C and 600.0 torr of pressure?
800.0 mL
How many sigma and pi bonds are in the a double bond and triple bond
Double is one sigma and one pi bond
Triple is one sigma and two pi bonds
Define exothermic and endothermic
Endothermic is when heat is absorbed, exothermic is when heat is released
A 75 g piece of metal is heated from 20°C to 100°C by absorbing 1500 J of heat. What is the specific heat capacity of the metal?
0.25 J/C
2 C2H2 (g) + 5 O2 (g) → 4 CO2 (g) + 2 H2O (g)
Calculate ΔH rxn from ΔHf values
ΔHf C2H2 = 226.6 kJ/mol
ΔHf CO2 = -393.5 kJ/mol
ΔHf H2O = -241.8kJ/mol
-2510.8 kJ
A balloon of air now occupies 10.0 L at 25.0 °C and 1.00 atm. What temperature was it initially, if it occupied 9.40 L and was in a freezer with a pressure of 0.939 atm?
−10. °C or 263 K
Determine the hybridization of BeCl2
sp
Determine what occurs to U when Q is negative and it is exothermic
U decreases
How much heat is required to heat 2.00 L of water from 20.0°C to 99.7°C? (Note: 1 L of water has a mass of approximately 1000 g, the specific heat capacity of water is 4.184 J/g C)
667,000 J
C3H8 (g) + 5 O2 (g) → 3 CO2 (g) + 4 H2O (g)
Calculate ΔHf of CO2 when the ΔH rxn is -2043 kJ
ΔHf C3H8 = −104.7 kJ/mol
ΔHf H2O = -241.8 kJ/mol
-393.5 kJ/mol
Calculate the minimum grams of sodium azide needed to fill a 60.0 L airbag at 760 torrs and 30 C. (1 atm = 760 torrs, R = 0.08206 L atm/mol K)
Chemical formula: 2 NaN3→ 2 Na + 3N2
2.40 mol
Determine the hybridization of CH2O
sp2
Give the definitions for Boyle’s law and Charle’s law
Boyle's law:
The volume of a fixed quantity of gas at constant temperature is inversely proportional to the pressure
Charle's law:
The volume of a fixed amount of gas at constant pressure is directly proportional to its absolute temperature
A 300 g sample of a metal absorbs 4500 calories of heat, causing its temperature to rise from 25°C to 75°C. What is the specific heat capacity of the metal in J/g°C? (Note: 1 calorie = 4.184 joules)
1.2552 J/C
2 NO2 (g) + H2O (g) → HNO3 (g) + NO (g)
Calculate ΔHf of NO2 when the ΔH rxn is 58.7 kJ/mol
ΔHf H2O = −241.8 kJ/mol
ΔHf HNO3 = −207.0 kJ/mol
ΔHf NO = 90.3 kJ/mol
33.2 kJ/mol
When 1.05 g of Hg2O is decomposed in a sealed container, the oxygen produced has a pressure of 0.514 atm at 35 C. What is the volume of oxygen produced? R = 0.08206 L atm/mol K
Chemical formula: 2 Hg2O → 4 Hg + O2
0.0619 L
Determine the hybridization and amount of sigma and pi bonds in NO3-
hybridization is sp2, has 3 sigma bonds, one pi bond
Determine what occurs to U when Q is positive and it is endothermic
U increases