JEE Class main Answered
Asked by familynhmpns | 04 Jul, 2022, 06:34: PM
Calorimetry is the process of measuring quantity of heat. Quantity of heat is meaured using calorimeter.
Calorimeter is thermally insulated metal container usually made of copper .
Initially , Calorimeter is filled with known quantity of water and has thermometer to measure the temperature.
When hot material at high temperature is transferred to calorimeter , heat is transferred from hot material to
water in calorimeter and the system comes to equilibrium. Aftser equilibrium is reached , final temperature is measured .
Quantity of heat transferred to calorimeter and water is the heat loss of transferred material .
Heat loss = mass × Specific heat × change in temperature = m × Cp × ( T - Tf )
where m is mass of transferred hot material that is at temeperature T and Cp is its specific heat
Heat gain by calorirmeter + water = ( mc Cpc + mw Cpw ) ( Tf - Ti )
where mc is mass of calorimeter and mw is mass of water that is at initial temeperature Ti .
Cpc is specific heat of calorimeter and Cpw is spaecific heat of water.
By conservation of energy , heat loss of transferred material equals heat gain of calorimeter and water
Hence we have , ( mc Cpc + mw Cpw ) ( Tf - Ti )= m × Cp × ( T - Tf )
Generally, all quantities except specific heat of transferred material Cp is known and measure quantities.
Hence specific heat of transferred material Cp is determined using above expression .
If specific heat of liquid is to be determined then instead of water we need to use that liquid in calorimeter.
To determine specific heat of liquid, specifi heat of transferred material should be known.
Answered by Thiyagarajan K | 04 Jul, 2022, 09:40: PM