Chemistry help

Question

024 (part 1 of 3) 10.0 points

Sulfuric acid reacts with sodium hydroxide

according to the equation

H2SO4 + NaOH −! Na2SO4 + H2O



Balance the equation for this reaction. What

mass of H2SO4 would be required to react

with 1.43 mol of NaOH?

Answer in units of g.

025 (part 2 of 3) 10.0 points

What mass of Na2SO4 is formed by this reaction?

Answer in units of g.

026 (part 3 of 3) 10.0 points

What mass of H2O is formed by this reaction?

Answer in units of g.

Answer 1

1. H₂SO₄ + NaOH ---> Na₂SO₄ + H₂O

 

To balance the equation, first notice that you have 2 Na's on the right and only one on the left.  So put a coefficient of 2 in front of NaOH and see what you get:

 

H₂SO₄ + 2NaOH ---> Na₂SO₄ + H₂O

 

Now the Na's balance (2 on each side) and the SO₄'s balance (1 on each side).  But there are 4 H's on the left and only 2 on the right.  So put a coefficient of 2 in front of the H₂O:

 

H₂SO₄ + 2NaOH ---> Na₂SO₄ + 2H₂O

 

This works.  (Count up everything to prove it to yourself.)

 

We're starting with 1.43 mol of NaOH.

 

2. How much H₂SO₄ is needed?  For every 2 mols of NaOH, you need 1 mol of H₂SO₄, so that means you need 1/2 of 1.43 = 0.715 mol of H₂SO₄.  Let's find the molecular mass of H₂SO₄:

 

H₂:  1.01 x 2 = 2.02

S:  32.06

O₄:  16.00 * 4 = 64.00

 

The total is 98.08.  So the total mass of H₂SO₄ needed is 98.08 * 0.715 = 70.13 g

 

3. How much Na₂SO₄ is produced:  The equation shows that for every 2 mols of NaOH, you get 1 mol of Na₂SO₄, so that means you get 1/2 of 1.43 = 0.715 mol of Na₂SO₄.The molecular mass is:

 

Na₂: 22.99 x 2 = 45.98

S:  32.06

O₄:  16.00 * 4 = 64.00

 

The total is 142.04.  So the total mass you get is 142.04 * 0.715 = 101.56 g.

 

4. Finally, how much H₂O is produced?  You get 1 mol of H₂O for each mol of NaOH, so you will get 1.43 mol of H₂O:

 

H₂: 1.01 x 2 = 2.02

O: 16.00

 

The total is 18.02, so will get 18.02 *1.43 = 25.77 g H₂O