Answer to Question #162472 in General Chemistry for Nousheen

Question

Calculate the grams of sulfur in 8.022x1025 formula units of Lithium sulfate.

Please answer with correct number of sig figs, and scientific notation

Answer 1

A mole of Lithium sulfate contains 6.02×10²³ molecules.

Proportion 1:

1 mol - 6.02×10²³ molecules

x mol - 8.022×10²⁵ molecules

$x = \frac{1 \times 8.022 \times 10^{25}}{6.02 \times 10^{23}} \\ = 133.25 \;mol$

M(Li₂SO₄) = 109.94 g/mol

m(Li₂SO₄) $= n \times M$

$= 133.25 \times 109.94 \\ = 14649.50 \;g$

M(S) = 32.06 g/mol

Proportion 2:

109.94 – 100 %

32.06 – y

$y = \frac{32.06 \times 100}{109.94} = 29.16 \%$

Proportion 3:

14649.50 – 100 %

z – 29.16 %

$z = \frac{14649.50 \times 29.16}{100}=4271.79 \;g$

Answer: 4271.79 g