Thermochemistry

ΔH value in an endothermic reaction is a positive number.

• True
• False

Tags

NGSS.HS-PS3-1

For the formula:
 Q= m c ∆T
The  units for specific heat are:

• g /J C
• °C/g J
• kJ/g
• J/g°C

Tags

NGSS.HS-PS3-4

As a reaction is taken place,  the student notices that the temperature has dropped. This indicates that the system has increased in energy. What type of process is this?

• Endothermic
• Exothermic

Tags

NGSS.HS-PS1-4

Using the heat equation, what would the formula look like if we were solving for change in temperature?

• Q m=∆T c
• Q/mc= ∆T
• Qm/c=∆T
• mcQ=∆T

A sample of iron receives 50.J of heat energy that raises the temperature of the iron 25.0°C. If iron has a specific heat of .10 J/g°C, what is the mass of the iron sample?

• 25g
• 30g
• 20g
• 50g

Tags

NGSS.HS-PS3-1

Calorimetry Question:

A piece of metal with a mass of 32.8 g is heated to 100.5°C and dropped into 138.2 g of water at 20.0°C. The final temperature is 30.2°C. What is the specific heat capacity of the metal?

• 2.56 J/g°C

• 0.391 J/g°C

• 5.29 J/g°C

• 3.50 J/g°C

Tags

NGSS.HS-PS3-2

NGSS.HS-PS3-4

In an exothermic process, the surroundings are are gaining energy.

• True
• False

Tags

NGSS.HS-PS1-4

The potential energy diagram of a reaction is shown. Which statement below is correct relating to this reaction?

• #1 represents the enthalpy change for this exothermic reaction.

• #2 represents the enthalpy change for this endothermic reaction.

• #3 represents the enthalpy change for this endothermic reaction.

• #4 represents the enthalpy change for this exothermic reaction.

Tags

NGSS.HS-PS1-4

During an exothermic reaction, heat content in the surroundings increases because

• heat energy is destroyed during reactions

• the reaction absorbs heat energy

• the energy contained in the reactants is lower then the products

• the energy contained in the products is lower than the reactants

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-4

The diagram represents two solids and the temperature of each. What occurs when the two solids are placed in contact with each other?

• Heat energy flows from solid A to solid B. Solid A decreases in temperature

• Heat energy flows from solid A to solid B. Solid A increases in temperature

• Heat energy flows from solid B to solid A. Solid B decreases in temperature.

• Heat energy flows from solid B to solid A. Solid B increases in temperature.

Tags

NGSS.HS-PS3-4