Water Of Crystallisation Titration Flashcards
1
Q
Primary standard that standardised HCl solution
A
Anhydrous sodium carbonate / Na2CO3
2
Q
Describe how 250cm^3 was prepared
A
Washing soda transferred to beaker and dissolved in deionised water.
Using a funnel, transfer the solution into volumetric flask.
Fill to 250cm with deionised water until the bottom of the meniscus is on the mark.
Stopper and invert several times.
3
Q
Indicator used + why
A
Methyl orange
Strong acid weak base titration
4
Q
Colour change
A
Orange —> Pink
5
Q
Number of moles HCl
A
0.12x21.5/1000 = 0.00258M
6
Q
Number of moles Na2CO3 neutralised
A
2HCl : Na2CO3 = 2:1 ratio
0.00258/2 = 0.00129M Na2CO3
7
Q
Number of moles Na2CO3 in 250cm^3
A
nx1000/v = 0.00129x1000/25
8
Q
Mass of Na2CO3 in 250cm^3
A
