What do scientists use to deterimine the temperature of a star

How many liters of water vapor can be produced if 108 grams of methane gas (ch4) are combusted at 312 k and 0.98 atm? show all work. pls ! will mark as brainliest

4.25g sample of solid ammonium nitrate dissolves in 60.0g of water in a coffee-cup calorimeter, the temperature drops from 22.0 c to 16.9 c. assume that the specific heat of the solution is the same as that of pure water. calculate delta(h) (in kj/mol nh4no3) for the solution proces.

Which samples do the atoms have the least kinetic energy