How many g of KCL would have to be dissolved in 60g H2O to give 25% by wt. of solution?
(gKCl)/(gKCl+60) = 0.25
solve for gKCl
To find the number of grams of KCl that need to be dissolved in 60g of H2O to give a 25% by weight solution, we need to understand what "25% by weight" means.
"25% by weight" refers to the mass percentage of KCl in the solution, which indicates the ratio of the mass of KCl to the total mass of the solution. In this case, the total mass of the solution is the sum of the mass of KCl and the mass of H2O.
To calculate the mass of KCl required, we can use the formula:
Mass of KCl = (Percentage by weight / 100) × Total mass of the solution
Let's substitute the values:
Mass of KCl = (25 / 100) × (60g + Mass of KCl)
Next, let's simplify the equation:
Mass of KCl = (25 / 100) × (60g + Mass of KCl)
Mass of KCl = 0.25 × (60g + Mass of KCl)
Now, let's distribute the 0.25 to both terms inside the parentheses:
Mass of KCl = 0.25 × 60g + 0.25 × Mass of KCl
Mass of KCl = 15g + 0.25 × Mass of KCl
To isolate the Mass of KCl on one side of the equation, let's subtract 0.25 × Mass of KCl from both sides:
Mass of KCl - 0.25 × Mass of KCl = 15g
Combining like terms:
0.75 × Mass of KCl = 15g
Now, let's solve for Mass of KCl by dividing both sides by 0.75:
Mass of KCl = 15g / 0.75
Mass of KCl = 20g
Therefore, 20 grams of KCl would have to be dissolved in 60 grams of H2O to obtain a 25% by weight solution.