Question

find the molarity of sol^n 0.2074g of CA(oH)2 in 40ml of sol^n​

Answer 1

Given:-

→ Mass of Ca(OH)₂ (solute) = 0.2074g

→ Volume of solution = 40mL

To find:-

→ Molarity of the solution

Solution:-

• Molar mass of Calcium (Ca) = 40g

• Molar mass of Oxygen (O) = 16g

• Molar mass of Hydrogen (H) = 1g

Hence, molar mass of Ca(OH)₂ :-

= 40 + 16×2 + 1×2

= 40+32+2

= 74g

Number of moles in 0.2074g of Ca(OH)₂ :-

= Given Mass/Molar mass

= 0.2074/74

= 2074/740000 moles

Now let's convert the volume of the solution from mL to L.

=> 1L = 1000mL

=> 40mL = 40/1000

=> 4/100 L

[ We have not converted the moles of solute and liters of solution in decimal for simplification in calculations in the next step ]

Molarity of a solution:-

= Moles of solute/Liters of solution

= [2074/740000]/[4/100]

= 2074/740000 × 100/4

= 518.5/7400

= 0.07 M [approximately]

Thus, molarity of the solution is 0.07 M.