Question

I will mark brainlist please help

Answer 1

Answer: 20) 2365 g

21) 22.39 grams.

22) 29.99 g

Explanation: 20) molarity is the no of moles of solute per unit volume.

We can calculate amount of CaCl2 required to prepare 0.1 M CaCl2 1000 ml solution.

we know that to prepare one ltr of 1 M solution of CaCl2 111 g required

Now consider x gram will require to prepare to

so that comparing above both condition

1000ml ×1M×X g=1000ml×0.1M×111g

X= 11.1 gram

X= 11.1 g of CaCl2

Hence 11.1 g of CaCl2 would be dissolved in 1.0L of a 0.100 M solution of CaCl2

21) How many moles of CaCl₂ in that solution?

;

;

.

What's the mass of that 0.20172 moles of CaCl₂?

Molar mass from a modern periodic table:

Ca- 40.078;

Cl- 35.45.

Molar mass of CaCl₂:

.

Mass of that 0.20172 moles of CaCl₂:

22) its a 3.0m solution so 1 litre of solution contains 3 moles of NaOH, 250ml of solution contains 0.25x39.9971 g/mol, so 250ml of this solution contains 0.75x39.9971=29.99g, or if you round it up 30.0g