Question

house?
report your answer to 2 significant figures.
molarity (m) = \frac{moles of solute}{liters of solution}
molarity is the amount of moles of a substance dissolved in a
liter of solution (usually a water - based solution).
lead ii carbonate
pbco₃
267.21 grams per
mol
1000 ml = 1l
solute:
.0000028 grams
lead (ii) carbonate
solution:
100 ml solution

Explanation:

Step1: Convert grams to moles

Use the formula \(n=\frac{m}{M}\), where \(m = 0.0000028\space g\) and \(M=267.21\space g/mol\) for \(PbCO_{3}\).
\(n=\frac{0.0000028}{267.21}\space mol\approx1.05\times 10^{-8}\space mol\)

Step2: Convert volume from mL to L

Given \(V = 100\space mL\). Since \(1000\space mL=1\space L\), then \(V=\frac{100}{1000}=0.1\space L\)

Step3: Calculate molarity

Use the formula \(M=\frac{n}{V}\). Substitute \(n = 1.05\times 10^{-8}\space mol\) and \(V = 0.1\space L\)
\(M=\frac{1.05\times 10^{-8}}{0.1}=1.05\times 10^{-7}\space M\approx1.1\times 10^{-7}\space M\) (rounded to 2 significant figures)

Answer:

\(1.1\times 10^{-7}\space M\)