Question

1. In the gaseous state, chlorine exists as a diatomic molecule Cl2 (Molar mass = 70.9 g/mol ). Calculate the number of moles of chlorine present in 100 g of chlorine gas. Express the quantity in moles to three significant figures.

2. Sodium hydroxide, NaOH , is a strong base that is used in industrial synthesis and processes such as making paper.What is the mass of 2.10 ×1022 molecules of NaOH (Molar mass = 40.0 g/mol )? Express the mass in grams to three significant figures.

3. Ascorbic acid, or vitamin C (C6H8O6 , molar mass = 176 g/mol ), is a naturally occurring organic compound with antioxidant properties. A healthy adult’s daily requirement of vitamin C is 70-90 mg . A sweet lime contains 2.86×10^−4 mol of ascorbic acid. To determine whether the ascorbic acid in a sweet lime meets the daily requirement, calculate the mass of ascorbic acid in 2.86×10^−4 mol of ascorbic acid. Express the mass in grams to three significant figures.

4. How many moles of methane are produced when 59.6 moles of carbon dioxide gas react with excess hydrogen gas? Express your answer with the appropriate units. For example, write the unit moles as mol.

5. How many moles of hydrogen gas would be needed to react with excess carbon dioxide to produce 30.6 moles of water vapor? Express your answer with the appropriate units. For example, write the unit moles as mol.

6. What is the molar mass of butane, C4H10 ? Express your answer to four significant figures and include the appropriate units.

7. How many moles of PCl5 can be produced from 28.0 g of P4 (and excess Cl2 )? Express your answer to three significant figures and include the appropriate units.

8. How many moles of PCl5 can be produced from 55.0 g of Cl2 (and excess P4 )? Express your answer to three significant figures and include the appropriate units.