Question

MISSED THIS? Read Section 7.4 (Pages 272-278), 7.6 (Pages 281-284); Watch KCV 7.4, 7.6, IWE 7.2, 7.7. Natural gas burns in air to form carbon dioxide and water, releasing heat. CH&(g) +O2(g)->CO2(g) + H20(g) AH 802.3kJ

Answer 1

First let us calculate heat required to raise the temperature

Q = mc∆T

Q = heat energy (Joules, J), m = mass of a substance (g)

c = specific heat (units J/g∙^oC), ∆ is a symbol meaning "the change in"

∆T = change in temperature (^oC Celcius)

Q = 50 g x 4.184 J/g∙^oC x 24 ^oC

Q = 5020.8 Joules or 5.020 Kilo Joules

One mole of Methane will release 802.3 Kilo joules of heat

Moles of Methane required to release 5.020 Kilo joules of heat = 5.020 /802.3 = 0.00625 Moles

molar mass of methane = 16 g/mol

Mass of Methane required to release 5.020 Kilo joules of heat = 0.00625 Mole x 16 g/mol = 0.1 gm

Hence 0.1 gm of methane is required to raise the temperature of 50 gm of water by 24^oC

Option B is correct answer