Answer:

Explanation:
Hello!
In this case, given the masses of copper, zinc and lead, it is possible to compute the moles via their atomic masses first:

Now, we compute the atomic percentages as shown below:

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<h2>
Hello!</h2>
The answer is:
The percent yield of the reaction is 32.45%
<h2>
Why?</h2>
To calculate the percent yield, we have to consider the theoretical yield and the actual yield. The theoretical yield as its name says is the yield expected, however, many times the difference between the theoretical yield and the actual yield is notorious.
We are given that:

Now, to calculate the percent yield, we need to divide the actual yield by the theoretical and multiply it by 100.
So, calculating we have:

Hence, we have that the percent yield of the reaction is 32.45%.
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Answer:
9 mL.
Explanation:
Dosage of insulin is 90 mg
The concentration of insulin is 10 mg/mL
We need to find how many milliliters of the solution do you need to give the patient. It can be calculated as follows :

So, 9 mL of the solution is to be given to the patient.