Hello,people

Check please answers of the exercises.
Ex.1.40 g of zinc oxide was reduced by excess carbon. Determine the mass of the formed metal if the yield of the reaction product is 85%.
Ex.2.490 g of a 20% solution of sulfuric acid was neutralized with slaked lime Ca (OH) 2, and 60.6 g of calcium sulfate was obtained. Determine the yield of the product in% to the theoretical
Ex.3.Acetylene is produced by the interaction of calcium carbide with water. How many grams of acetylene will be obtained if 68 g of calcium carbide contains 7% of impurities and the yield of acetylene is 75% of the theoretical value.
№1.1)ν(ZnO)=0.494 mol
2)ν(Zn)=ν(ZnO)0.494 mol
3)m[theor.](Zn)=32 g
4)m[pr.](Zn)=27.2g
Answer:27.2.
№2.1)m(H2SO4)=98g
2)ν(H2SO4)=1 mol
3)m[theor.](CaSO4)=136g
4)η(CaSO4)=45%
Answer:45%.
№3.1)m(imp.)=4.76 g
2)m(CaC2)=63.24 g
3)m[theor.](C2H2)=26 g
4)m[pr.](C2H2)=19.5 g
Answer: 19.5.