my answer is D sorry if I'm wrong
Answer:
32.8%
Explanation:
All of the Pb⁺² species precipitated as lead(II) cromate, PbCrO₄ (we know this as excess K₂CrO₄ was used).
First we convert 0.130 g of PbCrO₄ into moles, using its molar mass:
- 0.130 g ÷ 323 g/mol = 4.02x10⁻⁴ mol PbCrO₄
There's 1 Pb⁺² mol per PbCrO₄ mol, so in total 4.02x10⁻⁴ moles of Pb⁺² were in the ethanoate sample.
We <u>convert those 4.02x10⁻⁴ moles of Pb into grams</u>:
- 4.02x10⁻⁴ mol * 207 g/mol = 0.083 g Pb
Finally we calculate the percentage composition of Pb:
- 0.083 g Pb / 0.254 g salt * 100% = 32.8%
The concentration of a solution of 192 grams dissolved to make 2150 mL of solution is 0.93M. Details about concentration can be found below.
<h3>How to calculate concentration?</h3>
The concentration of a solution can be calculated by dividing the number of moles of the substance by its volume.
no of moles of NH42CO3 = 192g ÷ 96g/mol = 2 mol
Concentration of solution = 2 moles ÷ 2.15L
Concentration of solution = 0.93M
Therefore, the concentration of a solution of 192 grams dissolved to make 2150 mL of solution is 0.93M.
Learn more about concentration at: brainly.com/question/22997914
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