Question

12) Sodium hydroxide reacts with sulfuric acid.

The equation for the reaction is shown.

2NaOH + H₂SO4 → Na2SO4 + 2H₂O

Which volume of 0.4 mol/dm³ sodium hydroxide reacts with 50.0 cm³ of 0.1
mol/dm³ sulfuric acid?

A 12.5 cm³

B 25.0 cm³

D 100.0 cm³

C 50.0 cm³

Please provide steps

Answer 1

To solve this problem, we need to use the balanced chemical equation and the concept of molarity to determine the volume of sodium hydroxide needed. Step 1: Write the balanced chemical equation. 2NaOH + HâSO4 â Na2SO4 + 2HâO Step 2: Determine the mole ratio between sodium hydroxide and sulfuric acid. From the balanced chemical equation, we can see that the mole ratio between NaOH and HâSO4 is 2:1. This means that we need two moles of NaOH for every mole of HâSO4. Step 3: Calculate the number of moles of sulfuric acid. n(HâSO4) = c x V = 0.1 mol/dm³ x 50.0/1000 dm³ = 0.005 mol where c is the concentration of sulfuric acid and V is the volume in dm³. Step 4: Calculate the number of moles of sodium hydroxide needed. Since the mole ratio is 2:1, we need twice as many moles of NaOH as HâSO4. n(NaOH) = 2 x n(HâSO4) = 2 x 0.005 mol = 0.01 mol Step 5: Calculate the volume of sodium hydroxide needed. c(NaOH) = n(NaOH) / V(NaOH) V(NaOH) = n(NaOH) / c(NaOH) = 0.01 mol / 0.4 mol/dm³ = 0.025 dm³ = 25 cm³ where c(NaOH) is the concentration of sodium hydroxide. Therefore, the answer is B) 25.0 cm³.

Answer 2

I got B - 25cm³

Step-by-step explanation:

First you need to find the no. of moles of H₂SO₄ and I used this formula.

no. of moles = concentration × vol.

Substitute the values;

no. of moles = 0.1 × (50/1000)

Therefore, you would have 0.005mol

Then, if 1 mole of H₂SO₄ gives me 0.005mol, 2 moles of NaOH would give me 0.01mol. You can use ratio for this part!

Now that we have the no. of mol for NaOH, we can finally calculate the volume of NaOH used in this reaction. I used this formula;

vol. of NaOH = no. of mol/concentration

I just simply moved the previous formula around and made vol. the subject this time!

Then, substitute the values;

Vol. of NaOH = 0.01/0.4

You should get 0.025dm³!

Now, we just simply have to convert 0.025dm³ into cm³ like so;

1 dm³ --> 1000cm³

0.025dm ³ --> 0.025 × 1000

And that would give you 25cm³!

I hope this helps! Please let me know if I have any misconceptions or miscalculations! :)