Thermodynamics HW

The SI unit of heat and energy is the __________.

• calorie
• heat
• joule
• watt

ΔH value in an endothermic reaction is a positive number.

• True
• False

How do you calculate Enthalpy of a reaction?

• ΔH = ΔH_products - ΔH_reactants

• ΔT = q / mC

• ΔG = ΔH -TΔS

• E = mc²

Which statement is true regarding endothermic reactions?

• a) Temperature change is positive and enthalpy change is positive
• b) Temperature change is positive and enthalpy change is negative
• c) Temperature change is negative and enthalpy change is positive
• d) Temperature change is negative and enthalpy change is negative

Endothermic reactions feel

• warm
• cold

Define 'Enthalpy'

• a) Energy stored in the movement of molecules in a substance
• b) The opposite of temperature
• c) The temperature of a molecule
• d) Energy stored in the chemical bonds in a substance

A reaction that gives out energy to the surroundings causes the surroundings ....

• temperature to drop

• temperature to rise

• temperature to remain constant

• temperature to vary

 _?_  is the amount of energy required to raise the temperature of 1 gram of any substance 1^oC.

• Specific heat
• A calorie
• Thermal energy
• Conduction

Do molecules generally move faster at 45 C or 106 C?

• 45 C because molecules have more energy than in 106C

• 106 C because molecules have more energy than in 45C

• 106 C because molecules have less energy than in 45C

• 45C because molecules have less energy than in 106 C

When you place the metal in boiling water, heat flows from the _________ to the _______.

• metal to the boiling water

• bottom of the metal to the top half of the metal

• bottom of the water to the top of the water

• boiling water to the metal