Answer:
0.75 moles of BaSO4
Step-by-step explanation:
Based on the balanced equation:
BaCl2(aq) + Na2S04(aq) --> 2NaCl(aq) + BaSO4(s)
1 mole of BaSO4 is obtained from 1 mole of BaCl2 when Na2SO4 is in excess.
That means if you add 0.75 moles of BaCl2, the moles of BaSO4 that could be obtained are the same:
0.75 moles of BaSO4