Question

doreen schmidt is a chemist. she needs to prepare 28 ounces of a 11% hydrochloric acid solution. find the amount of 14% solution and the amount of 7% solution she should mix to get this solution. how many ounces of the 14% acid solution should be in the mixture? ounces how many ounces of the 7% acid solution should be in the mixture? ounces

Explanation:

Step1: Set up equations

We know that the total amount of solution is 28 ounces, so $x + y=28$, which can be rewritten as $x = 28 - y$. Also, the amount of pure - acid equation is $0.07x+0.14y=0.11\times28$.

Step2: Substitute $x$ into the acid - equation

Substitute $x = 28 - y$ into $0.07x+0.14y=0.11\times28$. We get $0.07(28 - y)+0.14y=0.11\times28$.
Expand the left - hand side: $0.07\times28-0.07y + 0.14y=0.11\times28$.
$1.96+0.07y=3.08$.

Step3: Solve for $y$

Subtract 1.96 from both sides: $0.07y=3.08 - 1.96$.
$0.07y=1.12$.
Divide both sides by 0.07: $y=\frac{1.12}{0.07}=16$.

Step4: Solve for $x$

Since $x = 28 - y$, and $y = 16$, then $x=28 - 16 = 12$.

Answer:

The amount of 14% acid solution is 16 ounces.
The amount of 7% acid solution is 12 ounces.