Hi nursing students. Are you confused by percent problems?
To add the % sign, multiply by 100%. To remove the % sign, divide by 100%. 0.25 (100%) = 25%. 39%/100%= 0.39.
How about those percent strength problems? What exactly does 0.9% NaCl mean? First you must determine the type of solution.
A 0.9% NaCl solution is a w/v solution, because you weigh out the NaCl and you measure the volume of the solution. Now you have 0.9% w/v. The trick when doing problems is to substitute g for w and mL for v. Now the 0.9% NaCl solution is 0.9% g/mL and you can use this form in your calculations.
How many g of NaCl are in 300 mL of 0.9% NaCl solution?
300 mL (0.9% g/mL)(1/100%) = 2.7 g