Question

How much heat do you need to raise the temperature of 150 g of gasoline from -30oC to -15oC?

SUBSTANCE���������C(J/g-^0C)
WATER ��������� 2.05
IRON ��������� 0.46
ALUMINUM ��������� 0.90
GOLD ��������� 0.13
COPPER ��������� 0.39
AMMONIA (LIQUID)���������4.70
ETHANOL ���������2.44
GASOLINE���������2.22
WATER (LIQUID)���������4.18
WATER (VAPOR)���������2.08
Air (25^0C)���������1.01
OXYGEN���������0.92
HYDROGEN���������14.30

4.68 kJ

5.00 kJ

6.66 kJ

9.40 kJ,

Answer 1

Use the formula: Q=m*C*ΔT
Given: mass of gasoline= 150 g or 1.50 kg
temperature of gasoline = 2.22 KJ /Kg.K
ΔT = -30 + 15
= 15 °C
Then substitute each given to the formula.

Solution:
Q = 0.15 Kg • 2.22 KJ/Kg.K • 15
= 4.99
=5 KJ

The answer is the second option

Answer 2

According to this formula:
Q=m*C*ΔT
and when we have m of gasoline = 150 g = 0.15 Kg
and the specific heat of gasoline = 2.22 KJ/Kg.K
and ΔT = -30 + 15 = 15 °C
So by substitution in the Q formula, we can get the amount of the heat:
Q = 0.15 Kg * 2.22 KJ/Kg.K * 15
= 4.99 ≈ 5 KJ