A level Chemistry Practical

1,I have a trouble in making deductions ,for cation and anion tests!
2,I also have trouble in making observations for gases,because i fail to understand for which reaction should i place the litmus papers on the test tube. :? 

Place the litmus paper whenever you see the mixture in the test tube bubbling.

The Qualitative analysis is given at the back. First fall arrange your test tube in an order which you can work with quickly, don't just put them randomly to mix them up! Secondly, take small amounts of liquids in the test-tubes to get faster results. You only need an approximate volume to the one given in the qst. See the qualitative analysis for the reagent that you are using. For example you are using sodium hydroxide (aq) then see the column of sodium hydroxide(aq) and try to match the colour changed that happened, if any. Thats all that you need to do. Apart from this only practice will help.

then you should keep calm
dont just jump onto conslusions
slowly and carefully
take care not to be too slow too!!!
and as u go on writing  your observations , write somewhere next to it the ions u would go for i mean white precipitate for Al , Zn and Ca when NaOH is added
i think i am right
anyways
u gotta write it and then strike out as u proceed in the end ur left with the answer!