To make a 10% solution of NaCl, we need to know the weight of NaCl required for 100 mL of solution. This can be calculated using the formula:
mass of solute (NaCl) = % concentration * volume of solution
Here, we have a 10% solution, which means that for 100 mL of the solution, we need 10 g of NaCl.
To find the amount required for 3 L of the solution, we need to convert 3 liters to milliliters. There are 1000 mL in 1 L, so 3 L = 3000 mL. Now, we can calculate the amount of NaCl required using the formula:
mass of NaCl = % concentration * volume of solution
= 10% * 3000 mL
= 0.10 * 3000 mL
= 300 g
Therefore, we need 300 grams of NaCl to make 3 L of a 10% solution.