Question

If every gram of salt is 20.9% chlorine, how much is required to make a 220 ppm chlorine solution with 350 grams of water?

Answer 1

Answer:

The amount of salt required is 0.3685 grams.

Step-by-step explanation:

20.9% of 1 gram of salt is chlorine, which means the grams of chlorine in 1 gram of salt are

$\dfrac{20.9\%}{100\%} *1\: gram = 0.209g\: \text{chlorine}$

Now, to make 220 ppm solution, it must be that

$\dfrac{220}{10^6} = \dfrac{y}{350+y},$

where $y$ is the grams of chlorine required.

We rearrange the equation and solve for $y:$

$220(350+y) = 10^6y$

$77000+220y =10^6y$

$77000 = (10^6-220)y$

$y = \dfrac{77000}{999780}$

$\boxed{y= 0.07702g}$

since 1 gram of salt has 0.209 grams of chlorine, 0.07702g of chlorine corresponds to

$\dfrac{0.07701}{0.209} = 0.3685g {\text{ of salt. }$

Thus the amount of salt required is 0.3685 grams.