Question

the mass
Find
otassium hydroxide that
present in 200 cm3
200 cm's in am
of
aqueous solution​

Answer 1

Answer:

Firstly remember that,

SEMI-MOLAR MEANS MOLARITY OF SOLUTION IS 1/2.

So, we know that,

Molarity = no. of moles of solute/ Volume of solution(in litre)

Now, 150 cm *3 means 150 ml of solution or 0.15 litres.

Now, according to question

0.5 = n/ 0.15

Therefore , n = 0.075 , ( where n is no. Of moles of solute)

Now molar mass of KOH is (39 +16+1) = 56 g/mol

Now, we know that,

n = given mass/ molar mass

Therefore, given mass = 0.075 × 56 = 4.2 gms.

(Hope you get the explanation )