.produce 340 grams of carbon dioxide ( at STP? C_(3)H_(8)+5O_(2)arrow 3CO_(2)+4H_(2)O

To determine how many grams of propane (C3H8) are needed to produce 340 grams of carbon dioxide (CO2) at standard temperature and pressure (STP), we need to use stoichiometry.First, let's calculate the molar mass of CO2:C: 12.01 g/molO: 16.00 g/molMolar mass of CO2 = 12.01 g/mol + (2 × 16.00 g/mol) = 44.01 g/molNext, we need to find the number of moles of CO2 produced:Number of moles of CO2 = Mass of CO2 / Molar mass of CO2Number of moles of CO2 = 340 g / 44.01 g/mol ≈ 7.75 molesNow, let's look at the balanced chemical equation:C3H8 + 5O2 → 3CO2 + 4H2OFrom the equation, we can see that 1 mole of propane (C3H8) produces 3 moles of carbon dioxide (CO2). Therefore, we can set up a proportion to find the number of moles of propane needed:1 mole of C3H8 : 3 moles of CO2 = x moles of C3H8 : 7.75 moles of CO2Solving for x, we get:x = (7.75 moles of CO2) / 3 ≈ 2.58 moles of C3H8Finally, let's calculate the molar mass of propane (C3H8):C: 12.01 g/molH: 1.01 g/molMolar mass of C3H8 = (3 × 12.01 g/mol) + (8 × 1.01 g/mol) = 44.11 g/molNow, we can calculate the mass of propane needed:Mass of C3H8 = Number of moles of C3H8 × Molar mass of C3H8Mass of C3H8 = 2.58 moles × 44.11 g/mol ≈ 113.5 gramsTherefore, approximately 113.5 grams of propane (C3H8) are needed to produce 340 grams of carbon dioxide (CO2) at standard temperature and pressure (STP).