Heating

Question 1

3 States of Matter

Answer 1

Solid, Liquid, Vapor.

Question 2

Sensible Heat

Answer 2

Is the amount of heat added to or removed from a substance causing a change in temperature measurable by thermometer.

Question 3

Latent Heat

Answer 3

Is the amount of heat added to or removed from a substance causing a change in state, but not a change in temperature.

Question 4

Specific Heat

Answer 4

Is the amount of heat added to or removed from a substance changing the temperature of the substance 1 degree F.

Question 5

Water Specific Heats are

Answer 5

Ice (Solid) =.5 btu

Water (Solid) = 1 Btu

Steam Vapor = .5 btu

Question 6

Heat of melting

Answer 6

Is the amount of latent heat added to a solid to cause the change of state to liquid

Question 7

Heat of fusion

Answer 7

Is the amount of latent heat removed from a liquid causing a change of state to a solid.

Question 8

Heat of vaporization

Answer 8

Is the amount of latent heat removed from a vapor causing a change of state to a vapor.

Question 9

Sub-cooled liquid

Answer 9

Is a liquid cold below its saturated condition, and when sub cooled there is only liquid present

Question 10

Super heated Vapor

Answer 10

A vapor heated above it’s saturated condition. When in a superheated condition there is only vapor present.

Question 11

Saturated condition

Answer 11

This exists whenever liquid and vapor are present in the Sam container under the conditions. Since liquid and vapor must be present, saturated conditions only exists when vaporization or condensation is occurring.

Question 12

Btu = British thermal unit

Answer 12

Is the amount of energy required to heat or cool one pound of water.

Question 13

What is the Specific Heat of Air

Answer 13

.24 BTU

Question 14

Enthalpy

Answer 14

Definition

Question 15

Heat is in everything until:

Answer 15

Absolute 0 or (-460 degrees below 0 F) (-273 degrees below 0 C)

Question 16

Fusion or melting

Answer 16

The process of braking away from other and changing from solid to liquid

Question 17

The heat required to break up mutual attraction of the molecules so that the material changes from a solid to a liquid is

Answer 17

Latent heat of melting or latent heat of fusion

Question 18

____________ heat of a solid is the heat that is added or removed to change the temperature of a solid.

Answer 18

Sensible

Question 19

Molecules in a solid are help together by

Answer 19

Cohesion

Question 20

Some molecules near the surface can brake away form a solid and become vapor. This is

Answer 20

Sublimation

Solid to a vapor

Question 21

Changing from a liquid to a vapor

Answer 21

Boiling

Question 22

Change for a liquid to a vapor

Answer 22

Evaporation

Question 23

Temp. Oxygen changes states

Answer 23

Liquid -297 Solid -361

Question 24

Vapor to water

Answer 24

Sensible heat of vapor is removed to 212 F.(still a vapor)

970 btu are removed to change to water. (Still 212 F)

Sensible heat is removed to make the water 32F. (Still water)

Question 25

Water to ice

Answer 25

Sensible temp is removed to 32f. 144 Btu are removed to change the state. (Temp is still 32f) Sensible temp is removed below 32f to cool ice.

Question 26

Temp. With no heat

Answer 26

- 40 f for air conditioning.

Question 27

Total heat of water

Answer 27

Sensible heat of ice -40f to 32f. Latent heat of fusion of ice 32f. The sensible heat of water 32f to 65f.

Question 28

To heat of steam at 400f

Answer 28

Sensible heat of ice from -40f to 32f. Latent of fusion heat of ice to 32f. The sensible heat of water 32f to 212f. Latent heat of vaporization of water at 212f. Sensible heat of stem 212f to 400f.

Question 29

Btu fomula

Answer 29

Number of pounds of water X number of degrees the temperature is to be raised ——————————————————————— = the number of btu.

Question 30

Raising a material to a higher temperature

Answer 30

Multiply to pounds of the material by the degrees it is to be warmed. Multiply this amount by the heat of that particular material.

Question 31

Latent heat of fusion: changing ice to wat

Answer 31

Multiply the weight of water by the latent heat of water (144 btu)

Question 32

Heat water to boiling

Answer 32

25 pounds(weight of water) X. 180 degrees (change in temp from 32 to 212) X. 1.0 (the specific heat of water) ———————— =. 4500 btu

Question 33

Changing water to water vapor (25 pounds of water)

Answer 33

Multiply the weight of water times the latent heat of vaporization for water. 25 pounds (weight of water) X 907 btu (latent heat of water) ——————————————————— = 24,250 btu