0.5g sample of bronze containing Zn is dissolved in 100ml of acid. An aliquot of 25ml requred 10.25ml of EDTA. What is the percentage of zinc in the bronze sample?

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manishaasrimaninathan

To determine the percentage of zinc in the bronze sample, you need to first calculate the amount of zinc in the aliquot and then use that information to determine the amount of zinc in the entire sample.

Here are the steps to calculate the percentage of zinc in the bronze sample:

Step 1: Determine the amount of zinc in the aliquot using the volume of EDTA used:
Since 10.25 mL of EDTA was required to titrate the 25 mL aliquot, we can assume that all the zinc in the aliquot reacted with the EDTA.

Let's assume the concentration of the EDTA solution is C (in mol/L).
Therefore, the moles of EDTA used can be calculated as:
Moles of EDTA = C * volume of EDTA used (in L)

Now, since the stoichiometry of the reaction between zinc and EDTA is 1:1, the moles of zinc in the aliquot are also equal to the moles of EDTA used.

Step 2: Calculate the amount of zinc in the entire sample:
Using the information that the sample originally contained 0.5 g of bronze, let's convert the mass of zinc to moles:

Let's assume the molar mass of zinc (Zn) is M (in g/mol).
Moles of zinc in the aliquot = Moles of zinc in the sample = (mass of zinc in the aliquot) / M

Step 3: Calculate the percentage of zinc in the bronze sample:
The percentage of zinc in the bronze sample can be calculated using the following formula:
Percentage of zinc = (moles of zinc in the sample / total moles in the sample) * 100

Let's assume the molar mass of zinc (Zn) is M (in g/mol), and the molar mass of bronze is Mb (in g/mol).
The total moles in the sample can be calculated as:
Total moles in the sample = (mass of bronze sample) / Mb

Now you can substitute the values into the formula and calculate the percentage of zinc in the bronze sample.

Sample size in the titrated sample (25 mL) is 0.5 x 25/100 = ?

mols EDTA = M x L = ?
mols Zn = mols EDTA
grams Zn = mols Zn x atomic mass Zn
%Zn = (mass Zn/mass sample in 25 mL)*100 = ?