Formula units in 450 g of is 1.93 × 10²⁴ formula units.
<u>Explanation:</u>
First we have to find the number of moles in the given mass by dividing the mass by its molar mass as,
Now, we have to multiply the number of moles of Na₂SO₄ by the Avogadro's number, 6.022 × 10²³ formula units/mol, so we will get the number of formula units present in the given mass of the compound.
3.2 mol × 6.022 × 10²³ = 1.93 × 10²⁴ formula units.
So, 1.93 × 10²⁴ formula units is present in 450g of Na₂SO₄.
<u>Answer:</u> The mass of calcium chloride present in given amount of solution is 87.5 g
<u>Explanation:</u>
We are given:
Mass of solution = 277.8 grams
Also, 31.5 % (m/m) of calcium chloride in water. This means that 31.5 g of calcium chloride is present in 100 g of solution.
To calculate the mass of calcium chloride in the given amount of solution, we use unitary method:
in 100 g of solution, the mass of calcium chloride present is 31.5 g
So, 277.8 g of solution, the mass of calcium chloride present is
Hence, the mass of calcium chloride present in given amount of solution is 87.5 g