Heat and Enthalpy

q

100

If 200 grams of water is to be heated from 24.0°C to 100.0°C to make a cup of tea, this much heat must be added. The specific heat of water is 4.18 J/g∙C

63,536 Joules

200

Object A specific heat is 2.45 J/g∙°C and object B specific heat is 0.82 J/g∙°C. This object will have a higher temperature if the same amount of heat is applied to both objects.

What is object b?

300

The specific heat of wood is 2.03 J/g∙°C. This much heat is needed to convert 550 g of wood at -15.0°C to 10.0°C.

What is 27, 912 joules?

400

Granite has a specific heat of 800 J/g∙°C. This mass granite is needed to store 150,000 J of heat if the temperature of the granite is to be increased by 15.5°C.

What is 12.096 grams?

500

A 55 g block of metal has an original temperature of 15.0°C and 0.45 J/g∙°C. This is the final temperature of this metal if 4500 J of heat energy are added.

15.01818 Celsius

Specific Heat

100

This term represents the amount of heat needed to raise 1 gram of a substance by 1 degree Celsius.

What is specific heat?

200

Units of specific heat capacity?

What is J/ g C

300

Metals left in the oven will get hotter faster than glass left on the oven because metals have a _______ specific heat than glass.

What is lower?

400

Conductors have a high/low specific heat while insulators have a low/high specific heat.

What is low for conductors and high for insulators

500

A total of 54.0 joules of heat are absorbed as 58.3 g of lead is heated from 12.0°C to 42.0°C. This is the specific heat of lead (with units).

0.031 J/g C

Calorimetry

100

if the q for the water is 4040 J then the q for the reaction is...

What is -4040 J

200

This is how a calorimeter works.

What is you measure changes the water, determine the q for the water then CHANGE THE SIGN to determine the q for the reaction because any heat lost by the water was gained by the reaction and any heat gained by the water was lost by the reaction.

300

A 28.4 g sample of aluminum is heated to 39.4 C, then is placed in a calorimeter containing 50.0 g of water. Temperature of water increases from 21.00 C to 23.00 C. This is the amount of heat for aluminum.

What is -418 J

400

If I burn 0.315 moles of hexane (C6H14) in a calorimeter containing 5.65 kg of water, This is the heat produced from hexane if the water temperature rises 55.40 C. The heat capacity of water is 4.184 J/g C.

What is 1310 kJ?

500

A 2.50 g sample of zinc is heated, then placed in a calorimeter containing 65.0 g of water. Temperature of water increases from 20.00 C to 22.50 C. The specific heat of zinc is 0.390 J/g C. This is the initial temperature of the zinc. (final temperatures of zinc and water are the same)

What is 717?

Enthalpy

100

this is symbol for the net energy change of a reaction

What is delta H?

200

If the reactants have an energy of 304 kJ and the products have an energy of 4 kJ, the delta H for the reaction is.

What is -300 kJ?

300

If the products have an energy of 300 kJ and the reactants have an energy of 400 kJ the net enthalpy change is equal to.

What is -100 kJ?

400

If the forward reaction has an enthalpy change of -300 kJ, the reverse reaction has this enthalpy change.

What is 300 kJ?

500

When S8 and O2 combine to make SO2 2368 kJ are released from the reaction. This is the thermochemical equation for this reaction.

What is S8 + 8 O2 --> 8 SO2 + 2368 kJ

Endothermic/Exothermic

100

This type of reaction has heat leaving the system for the surroundings.

what is exothermic?

200

Hot packs are an example of this type of reaction.

What is exothermic?

300

This type of process is required to break bonds.

What is endothermic?

400

The type of reaction could have a change in enthalpy of 400 kJ.

What is endothermic?

500

Reactions can be endothermic, exothermic or ISOTHERMIC. Draw a reaction diagram for an isothermic reaction.