AP Chemistry Term 3 symbols review

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

A catalyst works by

• changing the order of the reaction
• increasing the temperature
• lowering the activation energy
• making the activated complex

What type of reaction is shown in the reaction pathway?

• endothermic reaction
• exothermic reaction

Endothermic reactions feel

• warm
• cold

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 this equation endo- or exo-thermic?

PCl₃ (s) + Cl₂ (g) --> PCl₅ (s) + energy

• endothermic

• exothermic

Is this equation endo- or exo-thermic?

2KNO₃ (s) + energy --> 2KNO₂ (s) + O₂

• endothermic

• exothermic

When new chemical bonds form, energy ____________.

• is taken into the system.

• is released from the system.

• stays the same in the system.

When the solids Ba(OH)₂ and NH₄SCN are mixed, a solution is produced and the temperature drops. Which statement about the energetics of this reaction is correct?

• The reaction is endothermic and ΔH is negative

• The reaction is endothermic and ΔH is positive

• The reaction is exothermic and ΔH is negative

• The reaction is exothermic and ΔH is positive