General Chemistry 2

What is thermal energy?

• the average overall volume of a system

• the total number of molecules in a system

• the kinetic energy of particles in a system

• the measure of temperature in a system.

What would be the greatest difference in using an open ceramic coffee mug rather than an insulated mug with a lid as a calorimeter?

• increased evaporation of the water

• loss of gaseous reactants

• inability to contain liquids

• exchange of energy with the surroundings.

Which statement defines calorimeter?

• a device that measures the heat that is gained or lost in a chemical change.

• a device that measures the potential energy of an element

• a device that is used to measure heat capacity

• a device that is used to measure temperature.

Which statement defines the heat capacity of a sample?

• the temperature of a given sample

• the temperature that a given sample can withstand

• the quantity of heat that is required to raise the sample’s temperature by 1°C (or Kelvin).

• the quantity of heat that is required to raise 1 g of the sample by 1°C (or Kelvin) at a given pressure.

Which statement describes how a basic coffee cup calorimeter works?

• It measures the mass of a substance given the specific heat and temperature of water in a cup of known size.

• t measures the density of a substance given the mass specific heat, and temperature of water in a cup of known size.

• It uses the mass and specific heat of water along with a

     pressure gauge to measure the gain or loss of energy when a substance is added.

• It uses the mass and specific heat of water along with a thermometer to measure the gain or loss of energy when a substance is added.

Which process is spontaneous?

• electrolysis of water into oxygen and hydrogen

• spreading of a strong fragrance of perfume in a room

• separation of sodium and chlorine from sodium chloride

• removal of iron fillings from a mixture by using a magnet.

What is enthalpy?

• It is the total concentration of the system

• It is the total heat content of the system

• It is the total pressure of the system

• It is the total disorder of the system.

How should the enthalpy of an intermediate step be manipulated when used to produce an overall chemical equation?

• Multiply the enthalpy by 1 if the chemical equation is reversed.

• Multiply the enthalpy by –1 if the chemical equation is reversed.

• Add 2 to the enthalpy if the coefficients must be doubled.

• Add 2 to the enthalpy if the coefficients must be cut in half.

Which process involves an increase in entropy?

• crystallization of a solute from a solution

• ice melting into liquid water

• iodine vapor forming solid iodine

• condensing a gas into a liquid

Which statement best describes why specific heat capacity is

often more useful than heat capacity for scientists when comparing

two materials?

• It is is an intensive property and does not depend on sample size.

• It is an extensive property and does not depend on sample size.

• It is an intensive property and depends on the sample size.

• It is an extensive property and depends on the sample size.