Answer:
0.845 g C
Explanation:
To find the mass of carbon (C) consumed, you need to (1) convert grams Na₂SO₄ to moles Na₂SO₄ (via molar mass from periodic table), then (2) convert moles Na₂SO₄ to moles C (via mole-to-mole ratio from reaction coefficients), and then (3) convert moles C to grams C (via molar mass from periodic table).
It is important to arrange the ratios/conversions in a way that allows for the cancellation of units. This can be done by making sure the desired unit is the numerator. The final answer should have 3 sig figs because the given value (5.00 grams) has 3 sig figs.
Molar Mass (Na₂SO₄): 2(22.99 g/mol) + 32.07 g/mol + 4(16.00 g/mol)
Molar Mass (Na₂SO₄): 142.05 g/mol
1 Na₂SO₄ + 2 C ---> Na₂S + 2 CO₂
Molar Mass (C): 12.01 g/mol
5.00 g Na₂SO₄ 1 mole Na₂SO₄ 2 moles C 12.01 g
----------------------- x -------------------------- x ----------------------- x --------------- =
142.05 g 1 mole Na₂SO₄ 1 mole C
= 0.845 g C
