Energy in Chemical Changes Mini-Review

For the following scenario, determine whether it is endothermic or exothermic:

A reaction that absorbs energy.

• Endothermic

• Exothermic

For the following scenario, determine whether it is endothermic or exothermic:

AB  +  Energy   →   A  +  B

• Endothermic

• Exothermic

For the following scenario, determine whether it is endothermic or exothermic:

Feels warm to the touch.

• Endothermic

• Exothermic

For the following scenario, determine whether it is endothermic or exothermic:

A log burning, producing heat.

• Endothermic

• Exothermic

For the following scenario, determine whether it is endothermic or exothermic:

∆ H = - 127 kJ

• Endothermic

• Exothermic

For the following scenario, determine whether it is endothermic or exothermic:

Feels cool to the touch.

• Endothermic

• Exothermic

 ___NaCl(s)  + ___F₂(g)  →  ___NaF(s)  +  ___Cl₂(g)

• 1, 1, 2, 2

• 3, 6, 3, 6

• 2, 1, 2, 1

• 1, 2, 1, 2

How does a catalyst lower the activation energy of a reaction?

• A catalyst increases the heat of reaction.

• A catalyst decreases the mass of the products.

• A catalyst provides an alternate pathway.

• A catalyst decreases the heat of the reactants.

Using the graph, is the reaction above endothermic or exothermic?

• Endothermic

• Exothermic

Using the graph, what is the enthalpy of the reactants?

• 100 kJ

• 110 kJ

• 120 kJ

• 140 kJ