How many mole of chlorine gas react with 0.100 mol of metal iron?
fe+cl2-> fecl2

                       2 mol Cl
.100 mol Fe  x = .05 mol Cl
                        1 mol Fe 

The independent variable is the type of music.the dependent variable is the pulse rate.the intervening variable is the age of the subject.if the mother does not like rock, her pulse is likely to not increase.the same might be true for the sister.the friend may like rap and gets excited.to establish cause/effect relationship, all of the subjects must be consistent.hope i .

The answer is probably c. xylem