Question

a 500 ml sample of water was heated from 10 k to 50 k. how much heat was gained?

Answer 1

To calculate the heat gained by water , we'll use: q = mcT

where, m = mass of substance in grams

c = specific heat of the substance (in Jg^-1K^-1)

T = Temperature change

step 1 : to calculate the temperature change:

Intial temperature , T1 = 10K , Final Temperature, T2 = 50K

T = T2 - T1 = 50K - 10K = 40K

Step 2 : to calculate mass of water

Density of water = 1g/mL , Volume of water = 500 mL

mass of water, m = Density of water X volume of water = 1g/mL X 500mL

mass of water, m = 500g

we know that the specific heat of water , c = 4.184 Jg^-1K^-1

step 3 ; To calculate heat gained :

q = mcT = (500g)(4.184 Jg^-1K^-1)(40K) = 83680 J

Heat gained, q = 83.68 kJ