# How many grams of NaCl are needed to prepare 35 kg of a 5 % (m/m) solution?

Jun 26, 2018

1.75 kg

#### Explanation:

To find the mass of NaCl, we'll use the formula:

"%(m/m)" = "mass of solute"/"mass of solution"*100%

NaCl in this case is the solute

Given from the question:
mass of solution = 35 kg
%(m/m) = 5%

Plug in the values:
"%(m/m)" = "mass of solute"/"mass of solution"*100%="mass of NaCl"/"35 kg"*100%=5%

$\text{mass NaCl} = \frac{5}{100} \cdot 35 = 1.75 k g$