Question

ratio 1 2 1 2 ★ score: 82.00 moles ? ? → moles? ? mass ? 0.005 g → 0.001167 g ? to test for the concentration of mercury (hg²⁺), a group of researchers poured an excess of ki (0.005 g) into a hair sample taken from a patient suffering from the disease. they found that it formed 0.001167 grams of the red precipitate hgi₂. now, we want to know how much mercury was in the sample. the first thing well notice is that from the balanced chemical equation we can see the ratio of hgi₂ to hg²⁺ is 1:1. this means that the moles of hgi₂ produced will be equivalent to the moles of hg²⁺ (or mercury in the hair sample). the problem is that we dont know how many moles of hgi₂ we have. we do know how many grams of hgi₂ we have, however. convert the gram value of hgi₂ into moles. how many moles is 0.001167 grams of hgi₂ equivalent to? the molar mass of hgi₂ 454.4 grams 1 mole moles of hgi₂

Explanation:

Step1: Use the formula for moles

The formula for calculating moles \(n\) is \(n=\frac{m}{M}\), where \(m\) is the mass and \(M\) is the molar mass.

Step2: Substitute the values

Given \(m = 0.001167\space g\) and \(M=454.4\space g/mol\). Then \(n=\frac{0.001167}{454.4}\).

Step3: Calculate the result

\(n=\frac{0.001167}{454.4}\approx2.57\times 10^{-6}\space mol\)

Answer:

\(2.57\times 10^{-6}\)