Question

Assume that the reaction of MeMgBr with ethylacetate proceeds with 100% conversion to give tert-butanol. The volume of 0.2 M solution of MeMgBr required to convert 10 mL of a 0.025 M solution of ethylacetate to tert-butanol is ................ mL. (Round off to one decimal place)

Hint:

To find the volume required for a reaction, use the equation \(\text{Volume} = \frac{\text{Moles of solute}}{\text{Molarity}}\).

Answer 1

Correct Answer: 2.5

Step 1: Use the molarity equation to calculate moles of ethylacetate.
The molarity equation is: \[ \text{Moles} = \text{Molarity} \times \text{Volume (in L)} \] The moles of ethylacetate is: \[ \text{Moles of ethylacetate} = 0.025 \, \text{M} \times 0.01 \, \text{L} = 2.5 \times 10^{-4} \, \text{mol} \] Step 2: Use the stoichiometric relationship.
Since the reaction goes to 100% conversion and the stoichiometry is 1:1, the moles of MeMgBr required will be equal to the moles of ethylacetate. Thus, the moles of MeMgBr required is also \(2.5 \times 10^{-4} \, \text{mol}\).
Step 3: Calculate the volume of MeMgBr solution.
The molarity of MeMgBr is 0.2 M, so the volume required is: \[ \text{Volume} = \frac{\text{Moles of MeMgBr}}{\text{Molarity of MeMgBr}} = \frac{2.5 \times 10^{-4}}{0.2} = 1.3 \times 10^{-3} \, \text{L} = 1.3 \, \text{mL} \] Thus, the volume of MeMgBr required is 1.3 mL.