What mass of benzoic acid can be made from a reaction where 4.87g benzyl alcohol is combined with 300mL of bleach? The reaction is conducted in water and dichloromethane. Describe a method of separating the benzoic acid from the sodium chloride byproduct after the reaction is complete.
To calculate the mass of benzoic acid that can be made, we need to know the stoichiometry of the reaction. Without that information, we cannot determine the exact mass of benzoic acid produced. However, I can provide you with the steps to find that information and instructions for separating benzoic acid from sodium chloride. Let's break it down:
1. Calculate the moles of benzyl alcohol (C₇H₈O):
- Convert the mass of benzyl alcohol (4.87g) to moles by using its molar mass (molecular weight).
- The molar mass of benzyl alcohol is the sum of the atomic masses of its constituent elements (C:12.01g/mol, H:1.01g/mol, O:16.00g/mol).
2. Determine the limiting reagent:
- Compare the mole ratio between benzyl alcohol and benzoic acid.
- Convert the volume of bleach (300mL) to moles of sodium hypochlorite (NaClO), assuming the bleach solution has a concentration of 100% NaClO.
- Use the balanced equation of the reaction to determine the mole ratio between benzyl alcohol and benzoic acid.
3. Calculate the theoretical yield of benzoic acid:
- Use the mole ratio to calculate the moles of benzoic acid that can be formed.
- Convert the moles of benzoic acid to grams by multiplying it by the molar mass of benzoic acid (C₇H₆O₂).
Now, regarding the separation of benzoic acid from sodium chloride after the reaction:
1. Transfer the reaction mixture to a separatory funnel:
- Remove the aqueous phase containing sodium chloride and benzoic acid from the reaction vessel.
- Use a separatory funnel, which allows for the separation of immiscible liquids based on their densities.
2. Add a solvent that selectively dissolves benzoic acid:
- Add a solvent that is immiscible with water but can dissolve benzoic acid, such as a low-boiling organic solvent like diethyl ether or dichloromethane.
- The benzoic acid will dissolve in the organic solvent, while the sodium chloride remains in the aqueous phase.
3. Separate the two phases:
- Close the separatory funnel and gently shake it to ensure proper mixing of the solvents.
- Allow the layers to settle, enabling the separation into an aqueous phase (containing sodium chloride) and an organic phase (containing benzoic acid dissolved in the organic solvent).
4. Drain and discard the aqueous phase:
- Carefully open the stopcock at the bottom of the separatory funnel.
- Collect and dispose of the lower aqueous phase, which contains the sodium chloride byproduct.
5. Recover the organic phase containing benzoic acid:
- Transfer the organic phase (containing dissolved benzoic acid) into a separate container.
- Use a rotary evaporator or similar method to evaporate the organic solvent, leaving behind the benzoic acid as a solid.
These steps describe a general method to separate benzoic acid from sodium chloride after the reaction is complete. However, it's important to note that this process may need modification depending on the specific reaction conditions and properties of the compounds involved.