Question

HQ2.45 Homework Unanswered What is the mass in milligrams of 4.30 moles of sodium? Give the answer to the correct number of significant figures. Do not write in scientific notation.

Answer 1

relation between wieght (mass) or molar mass

wieght (mass) \(=\) molex molar mass

here

$$ \begin{array}{c} \text { mole }=4.30 \mathrm{~g} 1 \mathrm{u} \\ \text { or molar mass }=22.989769 \mathrm{u} \end{array} $$

according to significant digit vule => The least number of significant figure in any number of the problem determined the number of significant figure in the answer.

e.g., Two significant figure is less than precise than three, so the answer has two significant figures.

So

$$ \begin{aligned} \text { weight (mass) } &=4.30 \mathrm{~g} / \mathrm{x} \times 22.989769 \mathrm{x} \\ &=98.8560067 \mathrm{~g} \end{aligned} $$