0.22g of carbon dioxide are dissolved in 400 cm3 of pure water. Calculate the concentration in mol/dm3 of the
solution produced.

0.0125mol/dm³

Explanation:

Given parameters:

Mass of carbon dioxide  = 0.22g

Volume of water  = 400cm³

Unknown:

Concentration in mol/dm³ =  ?

Solution:

Concentration is the amount of solute dissolved in a solvent.

The formula is expressed as;

    Concentration  =  

Number of moles  =

       Molar mass of CO₂   = 12 + 3(16) = 44g/mol

Number of moles  =   = 0.0005mol

Now,

             1000cm³  = 1dm³

             400cm³ =  = 0.4dm³

Insert the parameters and solve;

     Concentration  =  = 0.0125mol/dm³

"record the time to complete a chemical reaction" would most likely be part of a lab procedure.

the answer is d. 74.02