Discussion in 'International A And AS Level' started by XPFMember, Sep 29, 2011.
Hey please tell me if you get the answer
So doesn't it if to be C
all ASmoles questions solved
Moles & Stoichiometry : Past Paper Questions (9701 AS Chemistry MCQs): https://www.youtube.com/playlist?list=PL0U7Zwed3btQLUSSG9QtGUry32Q1D-_xU
Answer is C....
coniine is the major constituent of the poison ‘oil of hemlock’
Connine can be synthesised by reacting ammonia with a dibromo compound, X
What is the name of compound ?
pls help ;/
In the manufacture of sulfuric acid the reaction 2SO2(g) + O2(g) 2SO3(g) usually takes place at 400 °C and 1 atm pressure. In one industrial plant, it is decided to change the pressure to
What will be the consequences of this change
1 increased running costs
2 an increased percentage of sulfur trioxide in the equilibrium mixture
3 the rate of the backward reaction increases
The answer is A which 1,2 and 3 are correct
But how the rate of the backward reaction increases? I thought it should be decreases?
Q-Use of the Data Booklet is relevant to this question. Which sodium compound contains 74.2% by mass of sodium?
A sodium carbonate
B sodium chloride
C sodium hydroxide
D sodium oxide
Anyone?? Answer is D but I can't figure out why :/
In sodium oxide formula is Na2O
Ohh i understood, tysm
X is a salt of one of the halogens chlorine, bromine, iodine, or astatine (proton number 85).
The reaction scheme shows a series of reactions using a solution of X as the starting reagent.
X HNO3/ AgNO3 a precipitate excess NH3(aq) colorless solution
What could X be?
A sodium chloride
B sodium bromide
C potassium iodide
D potassium astatide
When x is added to silver nitrate a precipitate is formed which then dissolves in excess ammonia this dissolving shows that it will be a soluble halogen ....which means chloride. This is the main thing to be focused ...on reading the last step you might get confused but in excess of HNO3 it is actually the ammonia in the complex solution of Silver chloride that reacts to form ammonium nitrate and Silver chloride is left as precipitate.
Kindly solve these
May June 2017/11 q#20,24
For question 24
acid catalyst is added when dehydration is being done ....considering the diagram divide it into two parts from the upper oxygen to the lower right branch and similar division on the left side and then draw the structural formula for it will match the compound in part C.
got it thanks
Thanks, got it, any idea of question 20?
This is from the examination report
The most commonly chosen incorrect answer was C. C, pentan-3-one, would be reduced to pentan-3-ol. This will dehydrate to give cis and trans pent-2-ene; two isomers. B, butanone, would be reduced to butan-2-ol. This will dehydrate to give cis and trans but-2-ene and but-1-ene, three isomers.
Apart from above statement you have to focus on the statement ....Generating one product or mixture of products in case of option A one product is produced, in option B the product produced shows cis-trans isomerism which are in total three thus producing the most isomers..... same goes for the rest of the options.
JazakAllah Khairan kaseera
Actually i didn't have the examiner report so couldn't get any clue,thanks once again
Dinitrogen tetroxide dissociates into nitrogen dioxide on heating.
In an experiment the partial pressures of the gases at equilibrium were found to be NO2 , 0.33 atm; N2O4, 0.67 atm
What is the numerical value of Kp at the temperature of the experiment?
If anyone is generous enough to help me solve this question, i would really appreciate it!
Kp=(0.33)^2/0.67=0.16 .....option A
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