Question 8 Scoring: 12 points 1000g of water is heated by burning methane gas. (

Question

Question 8 Scoring: 12 points 1000g of water is heated by burning methane gas. (a) Cal culate the heat required to raise the temperature of 1000g of water from 2s'cto 100 C. The specific heat of water is 4.184/eC) (b) Cal e enthalpy of combustion of CH4 is-890.3 kJ/mol. (This means that on of one mole of methane produces 890. 3 kJ of heat energy.) culate the mass of methane required to heat the water. The molar mass of CHsis 16.04 g/mol. The the combustion of one mole (a) Heat required: (b) Mass of methane:

Explanation / Answer

The formula to find the heat is

Q=msT

Where m is mass

s is specific heat

T is change in temperature.

So Q=1000×4.184×(100-25) i.e. Q=313.8kJ

Combustion of one mole of methane gives 890.3 kJ but we only need 313.8kJ

So we will need 313.8/890.3 moles i.e. 0.35 moles of methane.

One mole of methane is 16.04g

So 0.35 moles is 0.35×16.04 i.e. 5.614 g of methane is required.

Related Questions

Navigate

• Browse (All)
• Browse Q
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.