20 points geniuses.
how does the law of conservation of mass apply to this reaction:
al + 3hcl --> h2 + alcl3?
a. the equation needs to be balanced. there are fewer hydrogen atoms in the equation than aluminum or chlorine.
b. the law of conservation of mass has already been applied. there is an equal number of each element on both sides of the equation.
c. hydrogen and chlorine need to be balanced. there is an equal amount of aluminum on each side.
d. only the hydrogen needs to be balanced. there are equal numbers of aluminum and chlorine.

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.

a gas, having a molecular weight of 13 kg/kmol and a kinematic viscosity of 0.25 cm2/s, flows through a pipe 0.25 m internal diameter and 5 km long at the rate of 0.4 m3/s and is delivered at atmospheric pressure.