Question

How much heat energy (Joules) is required to to raise the temperature of 120.0 g of water from -90 C to -5 C?

Answer 1

`"21.5 kJ"`

Explanation:

Use this equation

`"Q = mC"Δ"T"`

where

• `"Q ="` Heat
• `"m ="` Mass of sample
• `"C ="` Specific heat of sample (`"2.108 J/g°C"` for ice)
• `"ΔT ="` Change in temperature

`"Q" = 120 cancel"g" × "2.108 J"/(cancel"g" cancel"°C") × [-5 - (-90)] cancel"°C" = "21501.6 J" ≈ "21.5 kJ"`