Thermodynamics

What formula best defines specific heat?- heat/mass x temperature change

What is the heat required to raise the temperature of 1 gram of a substance 1°C or 1 K?- heat/mass x temperature change

How much energy does a copper sample absorb as heat if its specific heat is 0.384 J/g•°C, its mass is 8.00g, and it is heated from 10.0°C to 40.0°C?- 92.2 

92.2 joules are needed to raise the temperature of a 8.00-gram piece of copper from 10.0°C to 40.0°C. What is the specific heat of the copper piece? 0.384 J/g C

How much heat, in joules, is required to raise the temperature of 1.82 Kg of water by 3.320C?- = 25, 347.7 J

The quantity of energy released or absorbed as heat during a chemical reaction is called the- heat of reaction

What is the specific heat of a material if a 6.0 gram sample absorbs 50.0 joules when heated from 30°C to 50°C?

How much heat, in joules, is required to raise the temperature of 1.82 Kg of water by 3.320C?- 25,347.7

The specific heat of ethanol is 2.46 J/g°C. Calculate the heat energy required to raise the temperature of 193 grams of ethanol from 19°C to- 7600

 (ii) Calculate the amount of energy saved by using the copper container rather than an aluminium

container of mass 500g. (1 point) 256. J/C

On a hot day, the air temperature can increase dramatically, but the temperature of a body of water like the ocean does not change significantly. Water temperature does not change as quickly as the air temperature (for the same mass of air and water) because (MORE THAN ONE ANSWER)

• Water has a higher specific heat capacity than air and is therefore harder to heat

• Air has a lower specific heat capacity than water and therefore heats up more easily

A unit of energy needed to change 1 gram of a water by 1 degree Celsius.- specific heat

The temperature of the helium in the balloon increases by 10 degrees Celsius as it uses 400J of energy to expand. The specific heat capacity of helium is 5193 Jkg-1K-1 (Joules per kg per K).

The mass of helium in the balloon would be- 7 grams

1. If you were to touch a flask in which an endothermic reaction was occuring, the flask would feel

before the reaction started. (1 point)

• cooler than

2. The energy involved in the creation of a compound from its elements. (1 point)

• heat of formation

3. What units are used to measure heat? (1 point)

• Joules of kilojoules

4. A process that needs energy added to it for the reaction to take place is called has a

_heat of formation. (1 point)

• endothermic, positive

and

5. 30 grams of a metal at 100 degrees Celsius is placed in a calorimeter containing 100 mL of water at 21 degrees Celsius. After a few minutes, the temperature inside the calorimeter is 24 degrees Celsius. What is the specific heat of the metal? (1 point)

• 0.55 cal/gC

6. As the temperature of a sample increases, what happens to the average kinetic energy (AKE) of the particles of the sample? (1 point)

• AKE increases

7. Suppose that a chemical equation can be written as the sum of two other chemical equations.

If two reactions have AH values of -658 kJ and +458 kJ, what is AH for the reaction that is their sum? (1 point)

• -200 kJ

The Greek letter A stands for

• change in

It is impossible for ice to be colder than: (1 point)

• -273 degrees Celsius

A 13.8 g piece of zinc was heated to 98.8 C in boiling water and then dropped into a beaker containing 45.0 g of water at 25.0 oC. When the water and metal come to thermal equilibrium, the temperature is 27.1 OC. What is the specific heat capacity of zinc? [

(1 point)

What is the specific heat of silver if 42 J are used to heat a 5.0 gram sample from 0°C to 35.0°C? (1 point)

• 0.384 J/g°C

4. What is the specific heat of silver if 42 J are used to heat a 5.0 gram sample from 0°C to 35.0°C?

• 0.24 J/g°C

The energy involved in the creation of a compound from its elements. (1 point)

• heat of formation

3. Glass has a range of possible values for its specific heat capacity. The best explanation for this is because (1 point)

• it has a different chemical composition depending on how much silica (sand) is present in it

4. Calculate the energy required to produce 7 moles of Cl207 using the following balanced equation: 2 Cla+ 7 02+ 130 kcal -> 2 Cl207 (1 point)

• 455 kcal

9. 30 grams of a metal at 100 degrees Celsius is placed in a calorimeter containing 100 mL of water at 21 degrees Celsius. After a few minutes, the temperature inside the calorimeter is 24 degrees Celsius. What is the specific heat of the metal? (1 point)

• 0.13 cal/gC

10. It is impossible for ice to be colder than: (1 point)

• -273 degrees Celsius

Enthalpy change is the (1 point)

• amount of energy absorbed or lost by a system as heat during a process at constant pressure.

Determine the AH for the reaction: NO + ½ 02 → NOz Using the following information: ½ N2 + ½ 02 → NO ½ N2 + 02 → NOz 0 -22 kJ • +56 kJ • +124 kJ • -56 kJ ДН = + 90.0 kJ ДН = + 34.0 kJ

Answer= -56