You need to prepare 270ml of a 20% sucrose solution (w/v). Sucrose has a molecular formula of C12H22O11. How would you prepare this solution?

To prepare a 20% sucrose solution (w/v) with a total volume of 270ml, you will need to follow these steps:

Step 1: Calculate the amount of sucrose needed
To determine the amount of sucrose required, we need to consider the fact that the concentration is given in weight/volume (w/v). This means that for every 100ml of solution, 20g of sucrose will be present.

First, calculate 20% of 270ml:
20% = 20/100 = 0.20
Sucrose amount = 0.20 × 270ml = 54g

So, you will need 54g of sucrose to prepare 270ml of a 20% sucrose solution.

Step 2: Convert grams to moles
Since the molecular formula of sucrose is C12H22O11, we need to determine the molar mass of sucrose to convert grams to moles.

The molar mass of carbon (C) = 12.01 g/mol
The molar mass of hydrogen (H) = 1.01 g/mol
The molar mass of oxygen (O) = 16.00 g/mol

So, the molar mass of sucrose = (12.01 × 12) + (1.01 × 22) + (16.00 × 11) = 342.34 g/mol

To convert grams to moles, use the following formula:
Moles = Mass (g) / Molar mass (g/mol)

Therefore, the number of moles of sucrose = 54g / 342.34 g/mol = 0.1577 mol

Step 3: Prepare the solution
To prepare the solution, you will need a container with a volume of at least 270ml. Follow these steps:

1. Weigh 54g of sucrose using a balance.
2. Add the sucrose to the container.
3. Gradually add water to the container and mix until the total volume reaches 270ml.

Make sure to stir or shake the solution thoroughly to ensure uniform mixing.

By following these steps, you will have successfully prepared a 20% sucrose solution (w/v) with a volume of 270ml.