What is the Mr of MgCI2

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

How many grams of phosphorus are contained in 5.09 moles of phosphorus?

Liquid ammonia is produced at high temperatures and under great pressure in a tank by passing a mixture of nitrogen gas and hydrogen gas over an iron catalyst. the reaction is represented by the following equation. n2(g) + 3h2(g) → 2nh3(g) changing all but one experimental condition will affect the amount of ammonia produced. that condition is a) increasing the concentration of both reactants b) changing the temperature within the tank c) decreasing the pressure within the tank. d) increasing only the amount of nitrogen present.