Which statement about the following reaction is correct? ch4 (g) + 2o2 (g) yields co2 (g) + 2h2o(l) deltah = -890 kj reacting one mole of oxygen (o2) absorbs 445 kj of energy reacting one mole of oxygen (o2) releases 445 kj of energy reacting one mole of methane (ch4) absorbs 890 kj of energy reacting two moles of methane (ch4) releases 890 kj of energy

1 CH4 (g) + 2 O2 (g) > CO2 (g) + 2H2O(l) ΔH= - 890 kJ

1 mol           2 mol

1)  If ΔH has minus, it means "release". We need only "release" choices.

2) From reaction

1 mol CH4 (g)  "releases"  ΔH= - 890 kJ  - We do not have this choice.

2 mol  O2 (g)   "release" ΔH= - 890 kJ, so

1 mol  O2 (g)   "release" ΔH= - 445 kJ

Correct answer is B.

1

the transfer of heat by electromagnetic radiation is called thermal radiation . it is usually carried out by electromagnetic waves in an energy range just below the visible spectrum, which is the infrared range.

so the answer would be radiation.

: )