Unit 08- Thermo Part I Review Quiz (#3 Set)

Which instrument is used to measure the amount of energy (heat) transferred in a chemical reaction?

• Thermometer

• Calorimeter

• Barometer

• Spectrometer

What is the formula used to calculate the amount of heat transferred?

• Q = m/v

• Q = mcΔT

• Q = m + c + T

• Q = c/mT

According to the Law of Conservation of Energy, what happens to the total amount of energy in the universe?

• It increases over time

• It decreases over time

• It remains constant

• It is destroyed during reactions

What is enthalpy (H) a measure of during a chemical reaction at constant pressure?

• Quantity of mass transferred

• Quantity of energy transferred

• Quantity of temperature changed

• Quantity of volume changed

What type of value (positive or negative) indicates an exothermic reaction?

• Positive

• Negative

• Zero

• Both positive and negative

What is the standard enthalpy change (ΔH rx) for the combustion reaction of 1 mole of methane gas (CH₄), where water is formed?

• -890.2 kJ/mol

• -285.8 kJ/mol

• -601.6 kJ/mol

• -296.8 kJ/mol

Using Hess’ Law, which of the following best describes the process for calculating the enthalpy change of a reaction?

• Subtract the sum of the enthalpies of formation of reactants from the sum of the enthalpies of formation of products.

• Add the enthalpies of formation of reactants and products.

• Multiply the enthalpy of formation of reactants by the enthalpy of formation of products.

• Divide the enthalpy of formation of products by the enthalpy of formation of reactants.

What is the value of the enthalpy of reaction for SO₂(g) + ½ O₂(g) → SO₃(g)?

• -98.9 kJ

• 98.9 kJ

• -62.4 kJ

• 62.4 kJ

Which has more entropy: 1 g of liquid water or 1 g of steam?

• 1 g of steam

• 1 g of liquid water

• Both have the same entropy

• It depends on the temperature

Given the thermochemical equation: C₂H₂(g) + 5/2O₂(g) ---> 2CO₂(g) + H₂O(l), what is the value of ΔH°?

• -393.5 kJ

• -1299.5 kJ

• -285.8 kJ

• +1299.5 kJ