Q&A - Ask Doubts and Get Answers
Q

Henry’s law constant for CO_2 in water is 1. 67 x 108 Pa at 298 K. Calculate the quantity of CO_2 in 500 mL of soda water when packed under 2.5 atm CO_2 pressure at 298 K.

2.7    Henry’s law constant for  CO_{2}  in water is  1.67\times 10^{8}\; Pa at  298\; K. Calculate the quantity of  CO_{2}  in 500\; mL of soda water when packed  under  2.5\; atm CO_{2}  pressure at 298 \; K.

Answers (1)
Views

We know that , 

                              p = k_h\times x

 Pressure of CO =  2.5 atm   

We know that :              1\ atm = 1.01\times10^5\ Pa

So,   Pressure of CO2    =    2.53\times10^5 Pa   

By Henry Law we get,

                                x = \frac{p}{k_h} = \frac{2.53\times10^5}{1.67\times10^8} = 1.52\times10^{-3}

Taking density of soda water = 1 g/ml

We get mass of water = 500 g.

So,                                Moles of water :

                                                                  = \frac{500}{18} = 27.78

 Also,                                      x_{H_2O} = \frac{n_{CO_2}}{n_{H_2O}+n_{CO_2}} \approx \frac{n_{CO_2}}{n_{H_2O}}

So,            moles of CO2  =  0.042 mol

Using relation of mole and given mass, we get

               Mass of CO2  =   1.848 g.

Exams
Articles
Questions