If 14.7 g of calctum is placed in 11.5 g of water, what mass of hydrogen gas is produced?

I’m guessing you mean calcium?

Start off with a balanced equation:

2Ca + 2H20 ➡️ 2CaOH + H2

This is a limiting reactant problem. Solve for the amount of H2 gas produced with respect to each reactant using the mole ratio. The reactant that produces the least amount of H2 has is the answer.

a rain shadow is a dry region of land on the side that is protected against the prevailing winds of a mountain range. the prevailing winds are the winds that occur most of the time in a particular place of the earth

prevailing winds carry air toward the mountain range. as the air rises up over a mountain range, the air cools, water vapor condenses, and clouds form. on this side of the mountains, called the windward side, precipitation falls in the form of  rain  or snow. this dry air produces a  rain shadow.