Question

20 g salt is dissolved in water to prepare 20%(w/w) acqueous solution calculate the amount of salt added to this solution to make final concentration of 30%(w/w) ​

Answer 1

A percent w/v solution is calculated with the following formula using the gram as the base measure of weight (w):

% w/v = g of solute/100 mL of solution

Example 1:

Physiologic or isotonic saline is a 0.9% aqueous solution of NaCl.

0.9% saline = 0.9 g of NaCl diluted to 100 mL of deionized water,

where NaCl is the solute and deionized water is the solvent.

Example 1:

What is the % w/v of a solution that has 7.5 g of sodium chloride diluted to 100 mL with deionized water?

By definition, a percent w/v solution is the measure of weight per 100 mL. 7.5 g/100 mL = 7.5%

You can calculate this value as well:

X % = 7.5 g NaCl/100 mL of solution

X/100 = 7.5/100

Cross multiplying,

100X = 750

X = 7.5% w/v

Answer 2

Answer:

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Explanation:

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