Question

For this question use the balanced equation shown:Mg3N2 + 6 H2O → 3 Mg(OH)2 + 2 NH3If 9.69 grams of Mg(OH)2 are produced, how many moles of Mg3N2 are needed?Group of answer choices0.499 moles0.0554 moles29.1 moles188 moles1694 moles

Answer 1

0.0554 moles of Mg3N2 are needed.

Step-by-step explanation:

1st) From the given balanced quation we know that 1 mole of Mg3N2 reacts with 6 moles of H2O to produce 3 moles of Mg(OH)2 and 2 moles of NH3.

2nd) With the molar mass of Mg(OH)2 (58.32g/mol) we can convert moles to grams:

`3mol*(58.32g)/(1mol)=174.96g`

Now we know that 1 mole of Mg3N2 produces 174.96g of Mg(OH)2.

3rd) From the balanced equation we know that 174.96g of Mg(OH)2 are produced from 1 mole of Mg3N2, so to produce 9.69 grams of Mg(OH)2 we can use a mathematical rule of three to calculate the moles of Mg3N2 needed:

`\begin{gathered} 174.96g\text{ Mg\lparen OH\rparen}_2-1mole\text{ Mg}_3\text{ N}_2 \\ 9.69g\text{ Mg\lparen OH\rparen}_2-x=\frac{9.69g\text{ Mg\lparen OH\rparen}_2*1mole\text{ Mg}_3\text{ N}_2}{174.96g\text{ Mg\lparen OH\rparen}_2} \\ x=0.0554moles\text{ Mg}_3\text{ N}_2 \\ \end{gathered}`

Finally, 0.0554 moles of Mg3N2 are needed.