Problem 23 - Chemistry: The Central Science

Question

Suggest a method of separating each of the following mixtures into two components: (a) sugar and sand, (b) oil and vinegar.

Step-by-Step Solution

Answer

To separate sugar and sand, use dissolution and filtration by adding water to the mixture, stirring it, filtering the mixture, and then evaporating the sugar-water solution to obtain pure sugar. To separate oil and vinegar, use decantation by pouring the mixture into a separating funnel, waiting for it to separate due to their different densities, and then collecting the separated components.

Step 1: Separating sugar and sand

To separate sugar and sand, we can use a technique called dissolution and filtration. For this, we will need water, a beaker, and a filter paper or a filtration device. Step 1: Add water to the mixture Pour some water into the beaker containing the sugar and sand mixture. The sugar will dissolve, while the sand will remain as a solid. Step 2: Stir the mixture Stir the mixture to ensure that all the sugar dissolves properly in the water. Step 3: Filter the mixture Set up a filtration device using filter paper or a filtration device. Slowly pour the sugar-water solution onto the filter paper, allowing the sand to be caught by the filter while the sugar-water solution passes through. Step 4: Evaporate the sugar-water solution In order to obtain pure sugar from the sugar-water solution, you can either let it evaporate slowly at room temperature or heat the solution gently until all of the water has evaporated, leaving behind the sugar crystals.

Step 2: Separating oil and vinegar

To separate oil and vinegar, we can use a technique called decantation. For this, we will need a separating funnel. Step 1: Pour the mixture into a separating funnel Carefully pour the oil and vinegar mixture into a separating funnel. Make sure the funnel is secured and has a closed valve at the bottom. Step 2: Wait for the mixture to separate Allow some time for the oil and vinegar to separate due to their different densities. Oil is less dense than vinegar (aqueous solution), so it will float on top of the vinegar. Step 3: Collect the separated components Carefully open the valve of the separating funnel to release the vinegar (the bottom layer) into a container. Close the valve once all the vinegar has been collected. Then pour the oil which is left in the separating funnel into another container. By following these steps, we have successfully separated the components of each given mixture. We have used the dissolution and filtration method for separating sugar and sand and utilized the decantation method to separate oil and vinegar.