Unit 4 Quick Check Review

Cold packs absorb heat by dissolving salts. This would be an example of what type of reactions?

• Endothermic because it absorbs heat

• Exothermic because it absorbs heat

• Endothermic because it releases heat

• Exothermic because it releases heat

• Endothermic because heat is released

• Exothermic because heat is released

• Endothermic because heat is absorbed

• Exothermic because heat is absorbed

Select all of the endothermic reactions

• NH₄NO₃ + heat NH₄⁺ + NO₃^-

• NH₄Cl + heat NH₄⁺  + Cl^-

• 4Fe + 3O₂ Fe₂O₃ + heat

• • Changes of state: gas to liquid to solid

If you are presented with an exothermic reaction, which would contain more energy - the reactants or the products?

• the reactants - energy was released, therefore the products have less energy

• the products - energy was released, therefore the products have more energy

Cellular respiration involves the release of CO₂ from the break down of sugar after it reacts with oxygen. This process produces ATP energy for cells. Would this process be exothermic or endothermic?

• Exothermic

• Endothermic

Heat flows from ___________ to _________

• Hot to cold

• cold to hot

A glass of water is 21 degrees Celsius. An ice cube is -20C. Heat would flow from where to where?

• The water to the ice

• The ice to the water

• neither is correct

As Temperature increases, what happens tot he movement of the particles within a substance?

• They begin to move more rapidly

• They begin to slow down

• There is no change in movement

Thermal energy is the internal Kinetic energy of all the particles in any substance. It is measured as ___________, and the transfer of thermal energy is called ______________.

• Temperature; Heat

• Heat; Temperature

• Joule; Calorie

• Calorie ; joule

The amount of heat released

• q

• m

• c