Reaction Energy Test Review

Kinetic energy is measured in

• Newtons (N)

• Joules (J)

• Kilograms (kg)

• miles per hour (mph)

When ammonium nitrate dissolves in water, the solution gets cold. Which is true?

• Reaction is ENDOTHERMIC with positive ΔH
• Reaction is ENDOTHERMIC with -ΔH
• Reaction is EXOTHERMIC with a -ΔH
• Reaction is EXOTHERMIC with +ΔH

Which of the following correctly states the energy changes occurring when chemical bonds are formed and broken?

• Energy is released when bonds are formed and when they are broken.
• Energy is absorbed when bonds are formed and when they are broken.
• Energy is absorbed when bonds are formed and released when they are broken.
• Energy is released when bonds are formed and absorbed when they are broken.

Nitrogen reacts with hydrogen to produce ammonia according to the following equation:
N₂(g)+3H₂(g)→2NH₃(g); ΔH=-92 kJ mol^-1
The energy change for this reaction is best described as

• exothermic, because the net strength of the bonds in the products is greater than the net strength of the bonds in the reactants
• endothermic, because the net strength of the bonds in the products is greater than the net strength of the bonds in the reactants
• exothermic, because the net strength of the bonds in the products is less than the net strength of the bonds in the reactants
• endothermic, because the net strength of the bonds in the products is less than the net strength of the bonds in the reactants

What is a tool that measures the heat of chemical reactions?

• calorimeter
•  calorie
• Styrofoam™ cup
• none of these

Tags

NGSS.HS-PS1-4

What acts as the surroundings in the calorimeter?

• thermometer

• water

• styrofoam cup

• sample

Temperature is a measure of average [blank] energy of individual atoms.

• heat
• potential
• mechanical
• kinetic

Tags

NGSS.HS-PS3-2

ΔH value in an endothermic reaction is a positive number.

• True
• False

Tags

NGSS.HS-PS1-4

Which phase of matter has the greatest motion and least orderly arrangement?

• solid
• liquid
• gas

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

A catalyst works by

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