if 135.0 grams of h2o are produced during the combustion of methane, how many grams of methane were present at the beginning of the reaction

If you add 10ml of hot water to 10ml of cold water and the change in tempature 8°c calculate how much energy is gained by the cold water

Drag each label to the correct location on the chart. classify each reaction as endothermic or exothermic.

What is a main difference between a mixture and a pure substance? a mixture is only a liquid, but a pure substance can be in any state.a mixture looks the same throughout, but a pure substance does not.1 a mixture can vary in composition, but a pure substance has a set composlo a mixture can be made up of a single compound, but a pure substance car