Final answer:
To make a 20% solution of 150g of H₂SO₄, the mass of pure sulfuric acid required is 30g.
Step-by-step explanation:
To find the mass of pure sulfuric acid required to make a 20% solution of 150g of H₂SO₄, we can use the concept of mass percentage. A 20% solution means that 20g of H₂SO₄ is dissolved in 100g of solution. So, if we want to find the mass of pure H₂SO₄ required, we need to set up a proportion:
20g H₂SO₄ / 100g solution = x g H₂SO₄ / 150g solution
Cross multiplying, we get:
20g H₂SO₄ * 150g solution = 100g solution * x g H₂SO₄
Dividing both sides by 100g solution, we get:
x g H₂SO₄ = 20g H₂SO₄ * 150g solution / 100g solution
Simplifying, we find that x = 30g. Therefore, the mass of pure sulfuric acid required is 30g.