Question

A solution is prepared by adding 2 g of a
substance A to 18 g of water. Calculate
the mass per cent of the solute.​

Answer 1

Answer:

Mass percent of solute = mass of solutionmass of solute×100

Mass of solute = 2 g

Mass of solvent = 18 g

Mass of solution = 20 g

∴  Mass percent of solute =202×100

=10%

Hence, option B is correct.

Answer 2

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Mass % of solute (A) = 10%.

Step-by-step explanation :

Given that,

• Mass of solute, A = 2 g.
• Mass of solvent (water) = 18 g.

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We know,

Mass of solution = Mass of solute + Mass of solvent

⇒ 2 g + 18 g

⇒ 20 g.

Also,

$\sf{Mass\:\%\:of\:A=\dfrac{Mass\:of\:A}{Mass\:of\:solution}\times{}100}$

Putting the values, we get,

$\implies\sf{\dfrac{2\:g}{20\:g}\times{}100}$

$\implies\sf{\dfrac{100}{10}\%}$

$\implies \sf\pmb{Mass\:\%\:of\:A=}\:\bold{10\%.}$