Answer:
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Q.21 7.53*10²² atoms of O2 = 0.125 moles of O2
mass of one mole O2 = 16 grams
mass of 0.125 mole O2 = 2 grams
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Q.22 2.32*10²³ formula units of Al2(SO4)3 = 0.385 moles of Al2(SO4)3
mass of one mole Al2(SO4)3 = 342.15 grams
mass of 0.385 mole Al2(SO4)3 = 131.79 grams
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Q.23 1.50*10²² atoms of AgNO3 = 0.025 moles of AgNO3
mass of one mole AgNO3 = 169.87 grams
mass of 0.125 mole AgNO3 = 4.23 grams
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Q.24 2.55*10²² atoms of CaCO3 = 0.042 moles of CaCO3
mass of one mole CaCO3 = 100 grams
mass of 0.125 mole CaCO3 = 4.23 grams
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