Propane (C3H8, molar mass=44.09g/mol) can be prepared by the reaction of propene C3H6 molar mass=42.08 g/mol) with hydrogen (H2, molar mass=2.016 g/mol) according to the following balanced equation: C3H6+H2 C3H8
Assuming18.50g of propene and 28.50 of hydrogen are used, answer the following questions:
How many moles of propene are used? Be sure your answer has the correct number of significant figures.
If 2.05 of propane are formed, what is the percent yield of the reaction? Be sure your answer has the correct number of significant figures.
To determine the number of moles of propene used, we can use the molar mass of propene and the given mass of propene.
Molar mass of propene (C3H6) = 42.08 g/mol
Mass of propene used = 18.50 g
Number of moles of propene used = mass of propene used / molar mass of propene
Number of moles of propene used = 18.50 g / 42.08 g/mol
Number of moles of propene used = 0.4397 mol
Therefore, the number of moles of propene used is 0.4397 mol.
To calculate the percent yield of the reaction, we need to compare the actual yield (given) with the theoretical yield.
Theoretical yield can be calculated using stoichiometry from the balanced equation. According to the equation, C3H6 (propene) reacts with H2 (hydrogen) to form C3H8 (propane) in a 1:1 ratio.
Actual yield = 2.05 g (given)
Theoretical yield can be calculated by converting the moles of propene used to moles of propane produced, and then to grams.
Molar mass of propane (C3H8) = 44.09 g/mol
Number of moles of propane produced = number of moles of propene used = 0.4397 mol
Theoretical yield = number of moles of propane produced x molar mass of propane
Theoretical yield = 0.4397 mol x 44.09 g/mol
Theoretical yield = 19.38 g
Percent yield can be calculated by dividing the actual yield by the theoretical yield and multiplying by 100.
Percent yield = (actual yield / theoretical yield) x 100
Percent yield = (2.05 g / 19.38 g) x 100
Percent yield = 10.58%
Therefore, the percent yield of the reaction is 10.58%.