Question

A bottle of cold drink contains 200 mL liquid in which $C{O_2}$ is 0.1 molar. Suppose $C{O_2}$ behaves like an ideal gas, the volume of the dissolved $C{O_2}$ at STP is:
A) 0.244L
B) 22.4L
C) 0.448L
D) 44.8L

Answer 1

Hint: Multiply no. of moles of solute with 22.4 to get the volume of the dissolved $C{O_2}$ at STP. By using the formula of Molarity we can find the no. of moles of solute, as values of volume and molarity are given in question.

Formulas used:
Molarity = ${\dfrac{ No.\; of\; moles\; of\; the\; solute}{Volume\; of\; the\; solution\; in \;litres}}$
Volume of n moles of solute at STP= 22.4$ \times $ No. of moles of solute

Complete answer:
It is given the question that there is bottle of cold drink such that
Volume of the solution (V) = 200mL
We have to convert volume of solution into liters which can be done by dividing volume by 1000,
Therefore, Volume of solution in liters is = $\dfrac{{200}}{{1000}}$= 0.2 L
Amount of $C{O_2}$ present in solution i.e. molarity of solution = 0.1 molar
As we know that formula of molarity, so by using formula of molarity that is,
Molarity = ${\dfrac{ No.\; of\; moles\; of\; the\; solute}{Volume\; of\; the\; solution\; in \;litres}}$
Therefore by putting the values in the formula we get,
No. of moles of solute that is $C{O_2}$ = $0.1 \times $ $\dfrac{{200}}{{1000}}$ moles
Therefore, no. of moles of $C{O_2}$ = 0.02 moles
Now the volume of the $C{O_2}$ dissolved at STP as per formula will be,
Volume of n moles of solute at STP = 22.4$ \times $ no. of moles of solute
By putting values in it we get,
Volume of $C{O_2}$ dissolved at STP = 22.4$ \times $0.02
Hence Volume of $C{O_2}$ dissolved at STP = 0.448 liters

So the correct option is (C).

Note: Always remember that while calculating molarity volume of the solution should be in liters and not in any other unit. In the above solution volume is in mL so first we have to do the conversion to litres then go for further calculations otherwise the answer will be wrong.