Unit 11 Thermochemistry Test REVIEW

The energy stored in chemical bonds is called _____ potential energy.

• chemical

• kinetic

• potential

• substantial

• -81.0

• 81.0

• 199.0

• 0.421

The _____ is defined as the system along with the surroundings.

• universe

• surroundings

• earth

• system

Heat moves from ___ to ___.

• freezing to warm

• ice cold to molten lava hot

• hot to cold

• cold to hot

• 216

• -216

• -73/143

• 70

When the change in enthalpy is positive, the reaction is ​ ​ (a)   . When the change in enthalpy is negative, the reaction is ​ (b)   .

• endothermic
• exothermic

The temperature of a sample of a compound with a mass of 6.6 grams changed from 22 °C to 10 °C with the release of 325 J of energy. What is the specific heat of the compound?

• 4.10

• -4.10

• 0.00169

• -0.00169

How much heat is absorbed by 16.8 g of water when its temperature increased from 16.6 °C to 44.4°C? The specific heat of water is 4.184 J/g⁰C.

• 1954.1

• -1954.1

• 111.63

• -111.63

Exothermic reactions

• gain heat; the products have more energy than the reactants

• gain heat; the products have less energy than the reactants

• lose heat; the products have more energy than the reactants

• lose heat; the products have less energy than the reactants

When a nugget of pure gold is heated from 23.9°C to 729.9°C, it absorbed 3466 J of energy. The specific heat of gold is 0.129 J/g⁰C. Find the mass of the gold nugget.

• 38.06

• -38.06

• 315662.48

• -315662.48