Question

A solution of KOH has concentration of 56g/dm³.What is the mass of KOH contained in 500cm³ of this solution​

Answer 1

Answer :-

Required mass of the KOH solution is 28 grams .

Explanation :-

We have :-

→ Concentration of KOH = 56 g/dm³

→ Volume of the KOH solution = 500 cm³

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Firstly, let's convert the unit of volume of the KOH solution from cm³ to dm³ .

⇒ 1 cm³ = 10⁻³ dm³

⇒ 500 cm³ = (500 × 10⁻³) dm³

= (500/1000) dm³

= 0.5 dm³

Here, the concentration of KOH solution is actually it's density. So it's mass is :-

⇒ Mass/0.5 = 56

⇒ Mass = 0.5(56)

⇒ Mass = 28 grams

Answer 2

GIVEN DATA :

Concentration(density) of the KOH Solution = 56g/dm³

Volume of KOH = 500 cm³

TO FIND :

Mass of KOH = ?

SOLUTION :

Converting the unit volume of the KOH Solution from cm³ to dm³ :-

$\red➻ \: \: \boxed{ \rm 1 {cm}^{3} = {10}^{ - 3} dm ^{3} }$

then,

$\rm⇢ \: \: 500 {cm}^{3}$

$\rm⇢ \: \: (500 \times {10}^{ - 3} ) {dm}^{3}$

$\rm⇢ \: \: volume \: = \: 0.5 {dm}^{3}$

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So, Mass of Solution in terms of Concentration can be calculated as, by using

$\boxed{ \color{pink}\bf Mass = Density \times Concentration}$

then,

$\rm⇢ \: \: Mass = (0.5 \times 56)g$

$\rm⇢ \: \: \boxed{\color{lime} \rm Mass = 28g}$

FINAL ANSWER :

Mass of KOH Solution is 28g .