Social Sciences, asked by dhnnjy5871, 1 year ago

Calculate the percentage mass of water in crystals of washing soda.

Answers

Answered by ChitranjanMahajan
6

The percentage mass of water in crystals of washing soda is 63.38 %

• Washing soda crystals contain water of crystallisation. The chemical formula for the same is Na₂CO₃.10H₂O.

The percentage mass of water in crystals of washing soda is given by the ratio of mass of water present in a crystal to the total mass of the crystal, multiplied by 100.

• Molecules of water present in a crystal = 10

Therefore, mass of water present in a crystal = 10 × mass of each molecule of water

= 10 × (2 g +16 g)   [ H = 1 g, O = 16 g ]

= 10 × 18 g

= 180 g

Mass of one crystal of washing soda (Na₂CO₃.10H₂O) = (2 × 22 g) + 12 g + (3 × 16 g) + 180 g

= 44 g + 12 g + 48 g + 180 g

= 284 g

• Therefore, percentage mass of water in a crystal of washing soda = (180 g / 284 g ) × 100 %

= 63.38 %

Answered by topwriters
2

Percentage mass of water in crystals of washing soda = 63.38%

Explanation:

The chemical formula of washing soda is Na₂CO₃.10H₂O.

Molar mass of water in one molecule of washing soda  = 10 * molar mass of water, as each molecule of washing soda contains 10 water molecules.

= 10 × (2 +16)

= 180 g

Molar Mass of washing soda (Na₂CO₃.10H₂O) = (2 × 22) + 12 + (3 × 16) + 180

= 284 g

The percentage mass of water in crystals of washing soda = mass of water present in a crystal / total mass of the crystal * 100.

= (180 / 284) * 100

= 63.38%

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