How many grams of chromium are required to react with 125ml of 0.75m cuso4?

Chromium and copper (ii) sulfate react according the reaction below;
 2Cr + 3CuSO4 = 3Cu +Cr2(SO4)3
We can calculate the number of moles of CuSO4 present;
no of moles of CuSO4 = 0.75 × 0.125 = 0.09735 moles
According to the reaction the mole ratio is 2 : 3
Moles of Chromium = (0.09735 × 2)/3
                                = 0.0625 Moles
Mass of chromium = 0.0625 moles × 52 g/mole 
                               = 3.25 g of chromium

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 .