I was so thankful to see this exact question answered in a different way but I still don't understand how I'm suppose to know how or what to do on the following question. I just seem to always forget something.
Fifty milliliters of a solution of 50% dextrose is added to a liter of 0.45% NaCl with 2.5% dextrose to yield a solution with a final dextrose concentration of what percent?
50ml of D50% ( 50gm in 100ml ) consists of 25gm Dextrose
1000ml of N0.45%+D2.5% (2.5 gm in 100 ml) consists 25gm of Dextrose
Thus, total of 50 gm Dextrose in 1050ml of sol. (don't bother about Ns)
: 1050ml=50gm
100ml= 50/1050*100
= 4.76%
To find the final dextrose concentration of the solution, there are a few steps you can follow.
Step 1: Calculate the amount of dextrose in each solution.
- The first solution contains 50 milliliters (mL) of 50% dextrose. To find the amount of dextrose in this solution, use the formula: amount of dextrose = volume × concentration.
- Convert the volume from milliliters to liters: 50 mL ÷ 1000 = 0.05 liters.
- Calculate the amount of dextrose: 0.05 liters × 50% = 0.025 liters (or 25 mL).
- The second solution contains 1 liter of 2.5% dextrose. To find the amount of dextrose in this solution:
- Convert the concentration from percentage to a decimal: 2.5 ÷ 100 = 0.025.
- Calculate the amount of dextrose: 1 liter × 0.025 = 0.025 liters (or 25 mL).
Step 2: Calculate the total amount of dextrose after mixing the solutions.
- Add the amounts of dextrose from each solution together: 25 mL + 25 mL = 50 mL.
Step 3: Calculate the final volume of the solution.
- Add the volumes of the two solutions together: 50 mL + 1000 mL = 1050 mL.
- Convert the volume back to liters: 1050 mL ÷ 1000 = 1.05 liters.
Step 4: Calculate the final dextrose concentration.
- Divide the total amount of dextrose by the final volume: (50 mL ÷ 1.05 liters) × 100 = 4.76%.
Therefore, the final dextrose concentration of the solution is approximately 4.76%.