Given the constants below, calculate how much energy in Joules would be required to raise the temperature of 20.0 g of ice at -20.0 OC to steam at 120.0 OC.

Question

Given the constants below, calculate how much energy in Joules would be required to raise the temperature of 20.0 g of ice at -20.0 OC to steam at 120.0 OC.

Answer 1

This involves a series of calculations (Q represents heat in J).

1. Q_{-20 to 0C} = c_ice x m_ice x Δt = 2.06j/gC x 20g x 20C = 824 j
2. Q_melting = ΔH_f x m_ice = 334.72j/g x 20g = 6694.4 j
3. Q_{0 to 100C} = c_{l H2O} x m x Δt = 4.184j/gC x 20 g x 100C = 8368 j
4. Q_vap = ΔH_v x m_H2O = 2259.36 j/g x 20g = 45187.2 j
5. Q_{100 to 120} = 2.02j/gC x 20g x 20 C = 808 j

Add the result for each step to get the total # of joules needed.

answer = 61900 j to 3 sig figs.

Please check calculations