Qualification > Sciences
ALL CIE CHEMISTRY DOUBTS HERE !!
EMO123:
--- Quote from: angel_ak on June 01, 2011, 05:17:22 pm ---THANKEW!! ;D
0.200 mol of a hydrocarbon undergo complete combustion to give 35.2g of carbon dioxide and 14.4g of water as the only products. what is the molecular formula of the hydrocarbon?
1. C2H4
2. C2H6
3. C4H4
4. C4H8
--- End quote ---
for this we get a ratio of 1:2
but there are two options of 1:2 haydrocarbons
SkyPilotage:
--- Quote from: EMO123 on June 01, 2011, 05:28:30 pm ---for this we get a ratio of 1:2
but there are two options of 1:2 haydrocarbons
--- End quote ---
1:4 ratio...
N of Co2 = 35.2/44 = 0.8
N of H20 = 14.4/18 = 0.8
So ratio of CxHy:CO2:H2O
1 : 4 : 4
So there are 4 C and 8 H and 12O so the Hydrocarbon iS C4H8...
Vin:
18 A solid nitrate fertiliser reacts with an alkali to produce a gas which turns damp pH paper blue.
What is the empirical formula of this fertiliser?
A NO3 B NHO3 C NH2O D N2H4O3
D. How and why? :/
SkyPilotage:
--- Quote from: Vin on June 01, 2011, 05:38:38 pm ---18 A solid nitrate fertiliser reacts with an alkali to produce a gas which turns damp pH paper blue.
What is the empirical formula of this fertiliser?
A NO3 B NHO3 C NH2O D N2H4O3
D. How and why? :/
--- End quote ---
Ammonium salts + alkalis -----> ammonia gas...
So its NH4NO3 which has the molecular formule N2H4O3...
EMO123:
--- Quote from: SkyPilotage on June 01, 2011, 05:33:50 pm ---1:4 ratio...
N of Co2 = 35.2/44 = 0.8
N of H20 = 14.4/18 = 0.8
So ratio of CxHy:CO2:H2O
1 : 4 : 4
So there are 4 C and 8 H and 12O so the Hydrocarbon iS C4H8...
--- End quote ---
i am sorry to say but if the ratio is 1:4 then it will be C4H16
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