Thermochemistry

In an exothermic process heat absorbed.

• True

• False

Tags

NGSS.HS-PS1-4

A reaction is performed in a beaker with a temperature probe recording the temperature changes of the reaction.  If the temperature began at 15.0 degrees Celsius and ended at 27.5 degrees Celsius.  If the reaction is our system, is the system endothermic or exothermic?

• Exothermic
• Endothermic

Tags

NGSS.HS-PS1-4

Refer the the following question:
2N₂ + 3H₂ --> 2NH₃ + 46 kJ
How much energy would be produced if only 1 mol of nitrogen was reacted?

• 92 kJ
• 0.143 kJ
• 23 kJ
• 15 kJ

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-1

What mass of P₄ must be reacted to produce 5905 kJ of energy?
P₄ + 6Cl₂ --> 4PCl₃ + 2439 kJ

• 25.43 g
• 563.0 g
• 2.421 g
• 300.0 g

Tags

NGSS.HS-PS1-4

NGSS.HS-PS1-7

H₂ + 2 C + N₂ + 270.3 kJ --> 2 HCN
Is this reaction endothermic or exothermic?

• Endothermic 
• Exothermic

Tags

NGSS.HS-PS1-4

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

The amount of heat energy required to change the temperature of 12 g of gold from 45°C to 15°C is -47 J. What is the specific heat capacity of gold?

• 0.13 J/(g°C)

• 17,000 J/(g°C)

• 1600 J/(g°C)

• 0.065 J/(g°C)

Tags

NGSS.HS-PS3-4

The graph represents the uniform heating of a substance, starting with the substance as a solid below its melting point. Which line segment listed below represents an increase in potential energy and no change in average kinetic energy?

• Line segment AB

• Line segment BC

• Line segment CD

• Line segment EF

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-2

A cast iron skillet is used to fry bacon. For optimal frying, the pan must be heated to about 178 ^oC from a room temperature of 22.0 ^oC. It is known that 1.58 x 10⁵ J of heat energy are absorbed by the pan to reach the desired temperature and the specific heat of iron is 0.450 J/g ^oC. What must the mass of the skillet be?

• 12.7 kg

• 2.25 kg

• 110 kg

• 1.97 kg

Tags

NGSS.HS-PS3-1

Which of the following is an endothermic process?

• solid to gas
• liquid to solid
• solid to liquid
• gas to liquid

Tags

NGSS.MS-PS1-4