Heat transfer

Chem Lec- C1

Joule (J)

The SI unit of energy is ____

Calorie

________ which is defined as the amount of energy required to heat 1 g of water from 14.5 to 15.5°C.

4.184J

1 cal = ___ J

British thermal unit

BTU or _______ is defined as the amount of energy needed to raise the temperature of 1 lb of water by 1°F.

1055 J

1 Btu = ___ J

Calorie

is the energy unit used for food.

System

A ________ refers to the substance, body, reacting mixture or even region of space upon which we focus attention

Surroundings

The ___________ are everything that lies outside the boundaries of the system

Exothermic

When heat is released: it flows from system to the surroundings, the process is __________ and Q is negative (-)

Endothermic

When heat is absorbed: it flows from the surroundings to the system, the process is __________ and Q is positive(+).

heat capacity

The ____________, C, of a substance is defined as the amount of heat, Q, it releases or absorbs as it undergoes a temperature change, ∆T, of 1K.

Q=mcpΔT

How to calculate the magnitude of heat flow (Q)?

Energy

____ is always conserved

Calorimetry

The science of the accurate measurement of amounts of heat and the accompanying temperature changes of an observed body when it releases or absorbs heat is called _____

Calorimeters

Measurement of heat absorbed/released is carried out in calibrated devices called _____

Exothermic reaction

________ reaction is when the system is losing heat; the temperature of system/object will decrease; Heat will move towards the surroundings

Endothermic reaction

________ reaction is when the object/system gaining heat; temperature of the system/object will increase; Heat will move away from the surroundings, towards the system

Coffee-Cup calorimeter

is made up of two nested Styrofoam cups with a loose-fitting lid and a temperature measuring device such as a thermometer or a thermocouple.

constant-pressure calorimeter

Coffee-Cup calorimeter is also known as ________ because it is not vacuum sealed, i.e air can get inside the cup and air can flow outside the cup

bomb calorimeter

A _______ is a type of calorimeter that operates at constant volume

bomb calorimeter

This type of calorimeter is usually used to measure the energy produced by reactions that release large amounts of heat and gaseous products or those reactions that can be initiated using a spark like combustion reactions.

Constant-Volume Calorimeter

A bomb calorimeter is also known as ________

Bomb Calorimeter

This type of calorimeter is usually used to measure the energy produced by reactions that release large amounts of heat and gaseous products or these reactions that can be initiated using a spark like combustion reactions.