Aqueous lead(II) nitrate reacts with aqueous potassium iodide to produce aqueous potassium nitrate and lead(II) iodide as a precipitate. In this reaction 662 grams of lead(II) nitrate were combined with 332 grams of potassium iodide to produce 168 grams of potassium nitrate.

catya your not at all which answer i've seen you do this on another question!

option c: 1605.1 kj

the balanced chemical reaction for combustion of methane is as follows:

here, enthalpy formation of is -74.7 kj/mol, 0 kj/mol, -393.5 kj/mol and -241.82 kj/mol respectively.

the heat released or can be calculated as follow:

putting the values,

thus, heat released by combustion of 1 mol of methane is 802.54 kj/mol. thus, for 2 mol, heat released will be:

therefore, heat released by the combustion of 2 mol of methane is 1605.1 kj.