Question

If you react 1.31 mL of cyclohexanol, which has a density of 0.9624 g/mL, with 1.57 mL of 85% phosphoric acid, which has a density of 1.6845 g/mL, what is the theoretical yield (in g) of cyclohexene?

A) 1.41 g

B) 1.72 g

C) 2.03 g

D) 2.34 g

Answer 1

To calculate the theoretical yield of cyclohexene, the volume of reactants is converted to mass and the limiting reagent is identified. However, without the chemical equation or molar ratio, we cannot provide an accurate theoretical yield.

Step-by-step explanation:

The question pertains to the calculation of the theoretical yield of cyclohexene from a reaction involving cyclohexanol and phosphoric acid. The first step is to convert the volume of cyclohexanol to mass using its density. Then, calculate the mass of pure phosphoric acid in the 85% solution also using its density. In this kind of reaction, cyclohexanol is typically in excess, and phosphoric acid is the limiting reagent. However, without the balanced chemical equation, an assumption must be made that the reaction has a 1:1 molar ratio, which is not necessarily accurate for an acid-catalyzed dehydration. Therefore, further information is needed to precisely determine the theoretical yield of cyclohexene.

Answer 2

To find the theoretical yield of cyclohexene, multiply the volume of cyclohexanol by its density to get the mass, convert to moles, and use the 1:1 stoichiometry with cyclohexene's molar mass to find the mass of cyclohexene produced.

The correct option is A.

Step-by-step explanation:

The question is asking for the theoretical yield of cyclohexene when cyclohexanol is reacted with phosphoric acid. First, we need to calculate the mass of cyclohexanol by using its density and volume.

Then, we use the stoichiometry of the reaction to find the moles of cyclohexene that can be formed assuming 100% yield. Phosphoric acid is in excess, so it will not limit the reaction. Finally, we convert the moles of cyclohexene to grams using its molecular weight to get the theoretical yield.

Calculation Steps:

1. Calculate the mass of cyclohexanol: 1.31 mL x 0.9624 g/mL = 1.2607 g.
2. The reaction is: C6H11OH + H3PO4 → C6H10 + H2O + H3PO4. The stoichiometry is 1:1 for cyclohexanol to cyclohexene.
3. Calculate the moles of cyclohexanol: 1.2607 g / 100.16 g/mol = 0.012591 mol.
4. Calculate the mass of cyclohexene: 0.012591 mol x 82.14 g/mol = 1.0345 g.

This yield is theoretical, and the maximum amount of cyclohexene that can be produced under ideal conditions.

The answer is closest to option A) 1.41 g, which can be considered the theoretical yield of cyclohexene from the given amounts of reactants.

The correct option is A.