you need to make 20ml of a 20% glucose solution. I need to calculate the amount of glucose and water needed. I know that the M.W is 180.16 for glucose. Would I multiply 20ml times 20 percent first? Thank you!
To make a 20% glucose solution with a final volume of 20ml, you would follow these steps:
1. Calculate the amount of glucose needed:
- The percentage concentration is based on weight/volume, so a 20% glucose solution means 20g of glucose per 100ml of solution.
- We need 20ml of solution, so we can set up a proportion: 20g/100ml = x/20ml
- Cross-multiplying, we get 100x = 20 * 20
- Solving for x, we find x = 4g
So, you will need 4g of glucose.
2. Calculate the amount of water needed:
- The total volume of the solution is 20ml, and we already accounted for the glucose (4g).
- Therefore, the remaining volume will be filled with water: 20ml - 4ml (glucose) = 16ml of water.
So, to make a 20% glucose solution with a final volume of 20ml, you would need to mix 4g of glucose with 16ml of water.
To calculate the amount of glucose and water needed, it is important to understand the concept of concentration. Concentration is the amount of solute (glucose in this case) present in a given volume of solution (20ml).
To start, you are given that you need to make a 20% glucose solution. This means that the final solution will contain 20% of glucose by volume.
To calculate the amount of glucose, you need to determine 20% of 20ml. First, convert the percentage to a decimal by dividing it by 100: 20% = 0.20. Next, multiply this by 20ml:
0.20 x 20ml = 4ml
Therefore, you need to add 4ml of glucose to the solution.
To calculate the amount of water, you need to subtract the volume of glucose from the total volume of the solution. In this case, subtract 4ml from 20ml:
20ml (total volume) - 4ml (volume of glucose) = 16ml
Therefore, you need to add 16ml of water to the solution.
It is important to note that when calculating concentrations, it is done based on volume, not mass. The molecular weight (M.W.) provided for glucose (180.16 g/mol) is used to convert between mass and moles, but it is not directly relevant to this question since you are given the volume of solution required.
1 liter would contain .2 moles of glucose
So, 20ml would contain .2*.02 = .004 moles
.04 moles = 0.72g glucose