[shannel2596]

I know its a little long, but please help as much as you can to help me ( im homeschooled)

50 g of impure sodium carbonate is treated with excess sulphuric acid and 4.48 dm^3 of carbon dioxide is collected at STP while a solution of sodium sulphate is formed . The balanced equation is 2NaCO3 + H2SO4 = NaSO4 + CO2 +H2O

Calculate the percentage purity of the sodium carbonate

Second question

After all the carbon dioxide escaped from  the solution, the volume of the solution is adjusted to 250 cm^3. Calculate the concentration of this Na2SO4-solution

[Corribus]

The policy of the forum is that you have to show work to get help. What is your approach so far?

[DrCMS]

1) Start with correctly balancing the reaction equation  (check the formula for sodium carbonate and sodium sulphate).
2) How many moles of carbon dioxide in 4.48 dm³ at STP?
3) Using the correctly balanced reaction equation from 1 how many moles of sodium carbonate are needed to give the number of moles of carbon dioxide calculated in 2 above?
4) What is the mass of sodium carbonate for the number of moles calculated in 3 above?
5) Mass of sodium carbonate calculated above in 4 divided by the mass of the impure sample = % purity.

For the 2nd part you need to assume that the sodium sulphate only comes from the sodium carbonate part of the impure sample.
6) Knowing the number of moles of sodium carbonate calculated above in 4 and using the correctly balanced reaction equation from 1 how many moles of sodium sulphate does that produce?
7) As Molarity = moles per L, the number of moles of sodium sulphate calculated above in 6 dissolved in 250cm³ is what molarity?