Chemistry 11 grade

Question

How much heat, in joules is required to raise the temperature of 1.82 kg water by 3.32 C ?

What is specific heat of iron, if it required 1050 J of heat energy rise the temperature of 220.0 g of iron from 10.0 C to 20.4 C ?

Answer 1

Use the equation Q = mC_pΔT where "Q" is the heat energy in joules, "m" is the mass in grams, "C_p" is the specific heat in joules/(gram•°C) and ΔT is the temperature change in °C (or K):

1) Q = mC_pΔT

m = 1.82(1000) = 1820 grams

C_p for water (look this one up) = 4.184 j/(gram•°C)

ΔT = 3.32 °C

Q = (1820)(4.184)(3.32) = 25281 joules or 25300 joules

2) Q = mC_pΔT or Cp = Q/(m•ΔT)

Q = 1050 joules

m = 220.0 grams

ΔT = (20.4 - 10.0) = 10.4°C

Cp = 1050/(220•10.4) = 0.459 joules/(gram•°C) or 0.459 joules/(gram•K)