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How many grams of sulfuric acid are needed to produce 57.0 grams of water? Show all steps of your calculation as well as the final answer.

2NaOH+H2SO4 > 2Na2SO4+2H2O

User Cackle
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2 Answers

6 votes

Answer: 155.134 grams of sulfuric acid is needed.

Step-by-step explanation:

To calculate the moles, we use the following equation:


\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}

Moles of water:

Given mass of water = 57 grams

Molar mass of water = 18 g/mol

Putting values in above equation, we get:


\text{Number of moles}=(57g)/(18g/mol)=3.166moles

For the given chemical reaction, the equation follows:


2NaOH+H_2SO_4\rightarrow 2Na_2SO_4+2H_2O

By Stoichiometry of the reaction:

2 moles of water are produced by 1 mole of sulfuric acid

So, 3.166 moles of water will produced by =
(1)/(2)* 3.166=1.583moles of sulfuric acid.

Now, to calculate the mass of sulfuric acid, we use the moles equation:

Molar mass of sulfuric acid = 98 g/mol

Putting values in above equation, we get:


1.583mol=\frac{\text{Given mass}}{98g/mol}

Mass of sulfuric acid = 155.134 grams

Hence, 155.134 grams of sulfuric acid is needed.

User Daniel Kaplan
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5.6k points
4 votes

Answer:

155.16 g.

Step-by-step explanation:

  • Firstly, It is considered as a stichiometry problem.
  • From the balanced equation: 2NaOH + H₂SO₄ → 2Na₂SO₄ + 2H₂O
  • It is clear that the stichiometry shows that 2.0 moles of NaOH reacts with 1.0 mole of H₂SO₄ to give 2.0 moles of Na₂SO₄ and 2.0 moles of H₂O.
  • We must convert the grams of water (57.0 g) to moles (n = mass/molar mass).
  • n = (57.0 g) / (18.0 g/mole) = 3.1666 moles.
  • Now, we can get the number of moles of H₂SO₄ that is needed to produce 3.1666 moles of water.
  • Using cross multiplication:
  • 1.0 mole of H₂SO₄2.0 moles of H₂O, from the stichiometry of the balanced equation.
  • ??? moles of H₂SO₄ → 3.1666 moles of H₂O.
  • The number of moles of H₂SO₄ that will produce 3.1666 moles of H₂O (57.0 g) is (1.0 x 3.1666 / 2.0) = 1.5833 moles.
  • Finally, we should convert the number of moles of H₂SO₄ into grams (n = mass/molar mass).
  • Molar mass of H₂SO₄ = 98.0 g/mole.
  • mass = n x molar mass = (1.5833 x 98.0) = 155.16 g.
User Daniel Scocco
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