A chemical reaction occurs when reactant particles

• are separated by great distances

• have no attractive forces between them

• collide with proper energy and orientation

• convert chemical energy into nuclear energy

The energy needed to start a chemical reaction is called

• Potential energy

• Kinetic energy

• Activation energy

• Ionization energy

Given the potential energy diagram. Which numbered interval represents the activation energy of the reaction?

• 1

• 2

• 3

• 4

Tags

NGSS.HS-PS1-4

Given the potential energy diagram. Which interval represents the activation energy of the reverse reaction?

• A

• B

• C

• D

Tags

NGSS.HS-PS1-4

Given the potential energy diagram. Which letters represent the energy of the reactants and products, respectively?

• A and B

• A and D

• B and C

• B and D

Tags

NGSS.HS-PS1-4

In chemical reactions, which term is defined as the difference between the potential energy of the products and the potential energy of the reactants?

• Heat of fusion

• Heat of reaction

• Thermal conductivity

• Activation energy

Tags

NGSS.HS-PS1-4

Given the potential energy diagram. If each interval on the potential energy axis represents 100 kJ of potential energy, what can can be concluded from this diagram?

• The reaction is endothermic, and the heat of reaction is -200 kJ

• The reaction is endothermic, and the heat of reaction is +200 kJ

• The reaction is exothermic, and the heat of reaction is -200 kJ

• The reaction is exothermic, and the heat of reaction is +200 kJ

Tags

NGSS.HS-PS1-4

Given the balanced equation:

4Fe(s) + 3O₂(g) --> 2Fe₂O₃ + 1640 kJ

Which phrase best describes this reaction?

Tags

NGSS.HS-PS3-1

Which phrase describes the effect of adding a catalyst to a chemical reaction in order to increase the reaction rate?

• provides a different reaction pathway with a lower activation energy

• provides a different reaction pathway with a higher activation energy

• uses the same reaction pathway with a higher activation energy

• uses the same reaction pathway with a lower activation energy

Tags

NGSS.HS-PS1-5

In four beakers, a 2.0-centimeter strip of magnesium ribbon reacts with 100 milliliters of HCl(aq). Under which conditions will the reaction occur at the fastest rate?

• 0.1 M HCl at 20^oC

• 1.0 M HCl at 20^oC

• 0.1 M HCl at 50^oC

• 1.0 M HCl at 50^oC

Tags

NGSS.HS-PS1-5