# Question #f2b83

##### 1 Answer

The new concentration will be **1.00%**.

When doing percent concentration problems, you should always start by taking a closer look at your initial solution.

A *mass by volume percent concentration* is expressed as grams of solute, in your case sodium chloride, per **100 mL** of solution. A **1%** **m/v** solution will have **1 g** of solute in **100 mL** of solution

Your initial solution is **10.% m/v**, which means that it has **10 g** of sodium chloride in every **100 mL** of solution. Since you have *less* than 100 mL of solution, you'll have *less* than 10 g of sodium chloride in your sample

This is how much sodium chloride your initial solution contains.

Now, you want to increase the volume of the solution to **500 mL**. The key here is to realize that the amount of sodium chloride present **will not change**.

Your final solution will still have **5.0 g** of *smaller concentration*.

The volume is **10 times bigger**, so the concentration must be **ten times smaller**.