AP Chemistry Unit 6 Thermo Review

Front

What is the direction of heat flow when a hot metal comes in contact with cold water?

Back

Heat flows from the metal to the water, since heat moves from high temperature to low temperature.

Front

What is the enthalpy of combustion of methanol (CH3OH)?

Back

The enthalpy of combustion of methanol is -711 kJ⋅mol^-1.

Front

How do you calculate the mass of methanol needed to produce a specific amount of energy?

Back

Use the formula: mass = (energy required / enthalpy of combustion) × molar mass of methanol.

Front

What is the enthalpy change for the decomposition of hydrogen chloride (2 HCl -> H2 + Cl2)?

Back

The enthalpy change is +184 kJ.

Front

Which substance has a standard enthalpy of formation value of zero?

Back

F2(g) has a standard enthalpy of formation value of zero.

Front

What is bond enthalpy?

Back

Bond enthalpy is the amount of energy required to break one mole of a bond.

Front

What is the formula for calculating heat transfer (q) in a substance?

Back

q = m × c × ΔT, where m is mass, c is specific heat capacity, and ΔT is the change in temperature.

Front

What is specific heat capacity?

Back

Specific heat capacity is the amount of heat required to raise the temperature of one gram of a substance by one degree Celsius.

Front

What is the relationship between temperature and heat flow?

Back

Heat flows from areas of higher temperature to areas of lower temperature.

Front

What is the significance of a negative enthalpy change?

Back

A negative enthalpy change indicates that a reaction is exothermic, releasing heat.