Question

If 0.500L solution weighs 596g and contains 90.0g of oxalis acid, the concentration can be expressed as ?M, or ?(m/m)%, or ?(m/v)%.

Answer 1

Answer : The concentration can be expressed as, 1.99 M, or 15.1(m/m)%, or 18(m/v)%

Solution : Given,

Volume of solution = 0.5 L = 500 ml (1 L = 1000 ml)

Mass of solution = 596 g

Mass of oxalic acid, (solute) = 90 g

Molar mass of oxalic acid = 90.03 g/mole

First we have to calculate the concentration in terms of M(molarity).

Molarity : Molarity is defined as the number of moles of solute present in one liter of solution.

Formula used :
`M=(w_(solute))/(M_(solute)* V_s)`

where,

M = molarity of solution

`w_(solute)` = mass of solute(oxalic acid)

`M_(solute)` = molar mass of solute(oxalic acid)

`V_s` = volume of solution(in liters)

Now put all the given values in this formula, we get

`M=(90g)/(90.03g/mole* 0.5L)=1.99mole/L=1.99M`

Now we have to calculate the concentration in terms of (m/m)%

(m/m)% : It is defined as the mass of solute present in mass of solution in grams.

Formula used :
`(m/m)\%=(w_(solute))/(w_s)* 100`

where,

`w_s` = mass of solution

`(m/m)\%=(90g)/(596g)* 100=15.1%`

Now we have to calculate the concentration in terms of (m/v)%

(m/v)% : It is defined as the mass of solute present in one milliliter of solution.

Formula used :
`(m/v)\%=(w_(solute))/(V_s)* 100`

where,

`w_s` = mass of solution

`(m/m)\%=(90g)/(500ml)* 100=18%`