1. A compound whose empirical formula is CH₃ has a molar mass of 30 g/mol. What is its molecular formula? (3 points)

2. Find the molecular formula for each of the following compounds: (6 points) a) 30.5% nitrogen; 69.5% oxygen; molar mass of 46 g/mol NO₂ N₂O₄ N₃O₆ N₅O₁₀ N₇O₁₄ b) 2.67 g of carbon; 0.22 g of hydrogen; 7.11 g of oxygen; molar mass of 90 g/mol Hint: Start by calculating the empirical formula. 3. A gas sample of 17.0 g is constituted of 15.8 g of carbon, the rest being hydrogen. Given that the sample?s volume is 4.9 L at NTP conditions, calculate the molecular formula for this compound.(5 points) 4. A compound is constituted by mass of 22.6% phosphorus, the rest being chlorine. Given that a volume of 307 mL of the gas has a mass of 1.55 g at 25 ?°C and 90 kPa, find the molecular formula for this compound. (5 points) 5. A compound is constituted by mass of 52.1% carbon and 13.1% hydrogen, the rest being oxygen. Given that a volume of 5.33 L of this gas has a mass of 11.5 g at 13 ?°C and 110 kPa, find the molecular formula for this compound. (5 points)