GRAVIMETRIC AND VOLUMETRIC QUESTIONS:

[misaki]

Could anyone help me please?
STEP BY STEP APPROACH please.
1. I'm given, how do i find the productts of H2SO4(aq) + HClO4 (aq) ---> products.

2. The active ingredient in a certain toilet cleaner that clames to 'remove lime scale and rust' is HCL of approx 3 mol^-1. to analyse this toilet cleaner, a quality control chemist first delivered a 10.00 ml aliquote of toilet cleaner into a 250 ml volum. flask, then made up the diluted solution. she then titrated a 20.00 ml aliuqote of this diluted solution against sodium hydroxide solution of concentration 0.1044 molL^-1. The expected titre woud be?
P.s cud someone explain dilution factor to me? and how to know when to use it?

3. the ammount of pure HCl gas, in mol, that must be added to the solution to lower the pH from pH 12.0 - 2.0 would be?

4.when 1.0 mole of Cu3FeS3 and 1.0 mole of oxygen are mixed and allowed to react to the according eq.
2Cu3FeS3(s) + 7O2(g) ---> 2FeO + 6SO2
it is5/7 mole of Cu3FeS3. Why? ( I took a limiting/excess approach in my test and got the wrong answer. could someoen clarify my mistake)

5. A 2L sample of gaseous hydrocarbon is burnt in excress oxygen. The only products of the reaction are 8l OF CO2 and 10L of H2O, all at 100 C and 1 atm. the formula of hydro carbon is?

[Phantom-II]

2. I assume u mean 3mol/L? 3x0.01 x (20/250) = 0.0024 mol. n=vc, 0.0024/0.1044 = 0.0230, correct to 1 sig fig?
just remember, if something gets diluted the mol doesnt change, x the percentage of the dilute used, in this case 20/250

3. pH 12 - 2, (1/10^2)-(1/10^12), should get you 0.009999999999 mol of H+ ions per litre? volume of solution not specified

4. assuming u want the number of Cu3FeS3 reacted, it would be 1mol x (2/7), it looks like its asking for the Cu3FeS3 left?

5. work out number of CO2, number of H2O, find ratio(empirical formula) of C and H, should tell if its alkane alkene etc. work out number of hydrocarbon in the 2L, work out ratio between number of C and number of hydrocarbon, should tell u how many C per one hydrocarbon, then apply C:H ratio