HEAT CAPACITY
•The specific heat capacity (symbol c) of a substance is defined as the amount of energy needed to raise the temperature of 1 gram of the substance by 1 oC.
•Heat change gained or lost by a substance during a chemical reaction can be calculated by:
E = m x c x ΔT
where E is Energy (J); m is Mass (g); c is specific heat capacity (Jg-1oC-1); T is temperature (oC), Δ means change in.
•Example: 200 mL of boiling water is needed for a cup of tea.
•Calculate the energy required to make the water boil if the initial temp. was 18oC
•Specific heat capacity for water
is 4.184 Jg-1oC-1.
•Solution:
E = m x c x ΔT
= 200 x 4.184 x 82
= 68552 J = 68.552 kJ = 69 kJ
•The specific heat capacity (symbol c) of a substance is defined as the amount of energy needed to raise the temperature of 1 gram of the substance by 1 oC.
•Heat change gained or lost by a substance during a chemical reaction can be calculated by:
E = m x c x ΔT
where E is Energy (J); m is Mass (g); c is specific heat capacity (Jg-1oC-1); T is temperature (oC), Δ means change in.
•Example: 200 mL of boiling water is needed for a cup of tea.
•Calculate the energy required to make the water boil if the initial temp. was 18oC
•Specific heat capacity for water
is 4.184 Jg-1oC-1.
•Solution:
E = m x c x ΔT
= 200 x 4.184 x 82
= 68552 J = 68.552 kJ = 69 kJ