Question

A sample of barium nitrate is placed into a jar containing water. The mass of the barium nitrate sample is 27g. Assume the water is at 20 degrees C and the resulting barium nitrate solution is saturated. What mass of water is present in the jar?

Answer 1

Answer: The mass of water present in the jar is 297.7 grams.

Explanation:

We are given:

Mass of barium nitrate sample = 27 g

Solubility is defined as the maximum amount of solute that can be dissolved in a solvent at equilibrium.

The solubility of barium nitrate at 20°C is 9.02 g per 100 g of water

To calculate the mass of solution in which given amount of barium nitrate is dissolved, we apply unitary method:

9.02 g of barium nitrate is dissolved in 100 g of water

So, 27 g of barium nitrate will be dissolved in $\frac{100}{9.07}\times 27=297.7g$ of water

Hence, the mass of water present in the jar is 297.7 grams.

Answer 2

So we have Barium nitrate with a solubility of 8.7g in 100g water at 20°C.

using that relation
i.e.
8.7g (barium nitrate) =100g (water)
1g barium nitrate = 100/8.7 g water

27g barium nitrate = (100/ 8.7 ) × 27
= 310.34 g

therefore,
you need 310.34g of water is in the jar.