The solubility of potassium chloride at 20 degree celsius is 34.7g in 100g of water

The solubility of potassium chloride at 20 degree celsius is 34.7g in 100g of water.The density of the solution is 1.3g/ml.What is the w/v percentage of potassium chloride in the solution
Answer
Step-1: Let volume of the solution be V ml which contains 34.7gm of KCL and 100gm of water ?
Step-2: Density= (34.7+100)/V = 1.3gm/ml

Step-3:134.7=1.3V

Step-4:V=134.7/1.3 ml=103.61ml

Step-5:%w/v=mass of KCl in 100 ml of solution

Step-6:103.61 ml of KCL contains 34.7 g of KCl 

Step-7:100ml of KCL contains=34.7/103.61x100=33.49gm/100 ml 

m% salty

Question A Chemist has m gm of salt water that is m% salty.How many grams of salt must be add to make a solution that is 2m % salty? Answer At m% salty m gm of salt water has m2 /100 gm salt At 2m% salty water  the amount of  salt to be added is derived from the equation as bellow   2m/100=m2+x/x+m   Solve and get x=m2/100-2m