Question

A flask has a mass of 78.23 g when empty and 593.63 g when filled with water. When the same flask is filled with concentrated sulfuric acid, H2SO4, its mass is 1026.57 g. What is the density of concentrated sulfuric acid? (Assume water has a density of 1.00 g/cm3 at the temperature of the measurement.)

Answer 1

Answer:

1.84 g/cm³

Explanation:

A flask has a mass of 78.23 g when empty and 593.63 g when filled with water. The mass of water is:

m(water) = 593.63 g - 78.23 g = 515.4 g

The density of water is 1.00 g/cm³. The volume of water (and the flask) is:

515.4 g × (1 cm³/1.00 g) = 515 cm³

When the same flask is filled with concentrated sulfuric acid, H₂SO₄, its mass is 1026.57 g. The mass of H₂SO₄ is:

m(H₂SO₄) = 1026.57 g - 78.23 g = 948.34 g

948.34 g of sulfuric acid occupy a volume of 515 cm³. The density of sulfuric acid is:

ρ = 948.34 g / 515 cm³ = 1.84 g/cm³

Answer 2

Answer:

1.84 g/cm³

Explanation:

From Archimedes principle,

Relative density = weight of substance/weight of equal volume of water = Density of substance/ Density of water.

From the question,

mass of H₂SO₄/mass of water = Density of H₂SO₄/ Density of water

M'/M = D'/D........................... Equation 1

Where M' =  mass of  H₂SO₄, M = mass of  water, D' = Density of  H₂SO₄, D = Density of water

Note: Since The volume of the flask is constant

make D' the subject of the equation

D' = (M'/M)D........................ Equation 2

Given: M' = 1026.57-78.23 = 948.34 g, M = 593.63-78.23 = 515.4 g, D = 1.00 g/cm³

Substitute into equation 2

D' = (948.34/515.4)×1

D' = 1.84 g/cm³

Hence the density of concentrated sulfuric acid = 1.84 g/cm³