EL + DF practicals

Question 1

Sources of error in moles dtermination experiment?

Answer 1

1 - Not all compound reacted

2 - gas escape

Question 2

Heating to remove water from crystallisation?

Answer 2

1 - Weigh evaporating basin
2 - Add hydrated solid
3 - Heat to constant mass (heat, coo, wiegh untill mass doesn;t change)
4 - Obersvations: powder, steam, colour change

Question 3

What is water of crytslisation?

Answer 3

Water that is chemically bonded to the structure (hydrated)

Question 4

Hazrad when etrmining moles of compound in expiment?

Answer 4

All container to cool before re-weighing

Question 5

Errors in measuing volume of gas produced?

Answer 5

1 - Gas escape before bung placed on

2 -

Question 6

Making up a standard solution:

Answer 6

1 - Weigh out mass solid + add beaker
2 - Add deionized water + stir with glass rod
3 - Transfer to volumetric flask using funnel -rinsing beaker + rod + pouring into flask
4 - Make up vol. by adding deionised water -bottom meniscus on mark
5 - Stopper flask + invert to mix

Question 7

How to reduce error in standrad sol.

Answer 7

Use larger mass compound

Question 8

Titrtauion:

Answer 8

1 - Rinse bureet with solution uou will fill it with
2 - Fill burette
3 - Rinse grad. pipette with sol you wll fill it with
4 - Using pieppte transfer so. into conical flask
5 - Add indicator into flask
6 - carry out rough tittraion, adding solution itno flask utnill colour chnages - swirl
7 - Carry out till 2 concordant results
8 - Adf dropwise when near end point
9 - Mean titre