Questions: 17. Three moles of copper(II) sulfate, CuSO4, contains a. 4 b. 6.02 × 10^23 c. 1.51 × 10^23 d. 8 moles of oxygen. e. 12.04 × 10^23 f. 12 18. 0.400 moles of sucrose, C12H22O11, contains carbon atoms. a. 12 b. 6.02 × 10^23 c. 2.89 × 10^24 d. 5.02 × 10^22 e. 4.80 19. If 36 g of water is stored in a water bottle, how many grams of hydrogen are present? a. 1.0 g b. 2.0 g c. 3.0 g d. 4.0 g e. 8.0 g

Solution Steps

Copper(II) sulfate, \(\mathrm{CuSO}_{4}\), contains one copper atom, one sulfur atom, and four oxygen atoms per molecule. Therefore, one mole of \(\mathrm{CuSO}_{4}\) contains 4 moles of oxygen atoms. For three moles of \(\mathrm{CuSO}_{4}\), the number of moles of oxygen is: \[ 3 \, \text{moles of } \mathrm{CuSO}_{4} \times 4 \, \text{moles of oxygen per mole of } \mathrm{CuSO}_{4} = 12 \, \text{moles of oxygen} \]

Sucrose, \(\mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{11}\), contains 12 carbon atoms per molecule. Therefore, 0.400 moles of sucrose contains: \[ 0.400 \, \text{moles of sucrose} \times 12 \, \text{carbon atoms per molecule} = 4.80 \, \text{moles of carbon atoms} \] To find the number of carbon atoms, multiply by Avogadro's number (\(6.02 \times 10^{23}\)): \[ 4.80 \, \text{moles} \times 6.02 \times 10^{23} \, \text{atoms/mole} = 2.89 \times 10^{24} \, \text{carbon atoms} \]

Water, \(\mathrm{H}_{2}\mathrm{O}\), has a molar mass of approximately 18 g/mol (2 g/mol for hydrogen and 16 g/mol for oxygen). In 36 g of water, the number of moles is: \[ \frac{36 \, \text{g}}{18 \, \text{g/mol}} = 2 \, \text{moles of water} \] Each mole of water contains 2 moles of hydrogen atoms, so: \[ 2 \, \text{moles of water} \times 2 \, \text{moles of hydrogen per mole of water} = 4 \, \text{moles of hydrogen} \] The mass of hydrogen is: \[ 4 \, \text{moles} \times 1 \, \text{g/mol} = 4 \, \text{g of hydrogen} \]

Final Answer