Question

Please answers only , if you dont know do not reply you will be reported . 100 pts and brainliest.

Answer 1

Answer:

1. 77.5g,

2. 1.78 mol,

3. 281 g

4. add 80 mL of water

Explanation:

1. Molar mass (Na2O) = 2*23.0 + 16.0 = 62.0 g/mol

1.25 mol *62.0 g/1mol = 77.5 g Na2O

2. Molar mass (KOH) = 39.1 +16.0+1.0 = 56.1 g/mol

100 g * 1 mol/56.1 g = 1.78 mol KOH

3. Molar mass (KOH) = 39.1 +16.0+1.0 = 56.1 g/mol

5 mol * 56.1g/1 mol = 281 g KOH

4. M1V1 =M2V2

M - molarity, V- volume of solution

2.0M*20mL = 0.4M*V2

V2 = 2.0*20/0.4 = 100 mL

Volume of diluted solution = 100 mL

We have 20 mL of solution, we need 100 mL of solution,

so we need to add (100-20) =80mL of water.

Take 20 ml 2.0 Molar  of solution of HCl , add 80 mL of water, then we get 100 mL 0.4 M solution of HCl.