Convert the 4ml of 2-methyl-1-butene to grams using , density = mass/volume 2) Calculate the number of moles for 2-methyl-1-butene using the formula moles = mass /MW. 3) Use the number of moles of 2-methyl-1-butene to calculate the mass of 2-methyl-2-butanol expected (Theoretical mass) to form in the reaction 4) % yield of 2-methyl-2-butanol = actual mass of 2-methyl-2-butanol /theoretical mass x 100
The Correct Answer and Explanation is:
Step-by-Step Solution:
We will walk through the calculations based on typical values for 2-methyl-1-butene.
Given Data:
- Volume of 2-methyl-1-butene = 4 mL
- Density of 2-methyl-1-butene = 0.653 g/mL
- Molar mass (MW) of 2-methyl-1-butene = 70.13 g/mol
- Molar mass (MW) of 2-methyl-2-butanol = 88.15 g/mol
- Assume actual mass of 2-methyl-2-butanol obtained = 2.5 g
1) Convert 4 mL of 2-methyl-1-butene to grams:
We use the formula:
Mass = Density × Volume
Mass = 0.653 g/mL × 4 mL = 2.612 grams
2) Calculate the number of moles for 2-methyl-1-butene:
We use:
Moles = Mass ÷ Molar mass
Moles = 2.612 g ÷ 70.13 g/mol ≈ 0.03725 moles
3) Calculate the theoretical mass of 2-methyl-2-butanol expected:
The reaction produces 2-methyl-2-butanol from 2-methyl-1-butene in a 1:1 mole ratio. Therefore, moles of 2-methyl-2-butanol = 0.03725 moles
Mass = Moles × Molar mass
Mass = 0.03725 moles × 88.15 g/mol ≈ 3.28 grams
4) Calculate percentage yield of 2-methyl-2-butanol:
We use:
% yield = (Actual mass ÷ Theoretical mass) × 100
% yield = (2.5 g ÷ 3.28 g) × 100 ≈ 76.22 %
Explanation:
This process involves several important chemical calculations commonly used in laboratory experiments to analyze reaction efficiency. First, the mass of 2-methyl-1-butene is calculated by multiplying its density by the given volume. Density relates mass and volume, so using 0.653 g/mL for density and 4 mL for volume provides a mass of approximately 2.612 grams.
Next, to determine the number of moles of 2-methyl-1-butene present, the mass is divided by its molar mass, which is 70.13 grams per mole. This yields around 0.03725 moles of 2-methyl-1-butene available for the reaction.
The chemical reaction is designed to convert 2-methyl-1-butene to 2-methyl-2-butanol with a 1:1 mole ratio. Therefore, the number of moles of product expected theoretically is also 0.03725 moles. Using the molar mass of 2-methyl-2-butanol, which is 88.15 grams per mole, the theoretical mass of product is calculated to be approximately 3.28 grams.
Finally, the efficiency of the reaction is assessed using the percentage yield formula. The actual mass obtained from the reaction is divided by the theoretical mass and multiplied by 100. In this example, the actual yield is 2.5 grams, resulting in a percentage yield of about 76.22 percent. This value reflects how successfully the reaction converted the reactant to the desired product, with typical yields rarely reaching one hundred percent due to side reactions or experimental losses.
