- Messages
- 222
- Reaction score
- 25
- Points
- 38
The mixture is distilled...
Aaaah ok.... I guess I missed that part Thanks
We are currently struggling to cover the operational costs of Xtremepapers, as a result we might have to shut this website down. Please donate if we have helped you and help make a difference in other students' lives!
Click here to Donate Now (View Announcement)
The mixture is distilled...
Hello there!Hi,
I need help as i am not able to understand fully the markscheme answer.
Q. the trend of solubility of group2 sulfates.
Q. the trend of stability of carbonates and nitrates of group2 metals.
thankyou...
Can you explain it in terms of L.E and enthaloy of Hydration...Hello there!
The trend of solubility of group 2 sulfates decreases down the group. remember that barium sulfate is sparingly soluble salt.
The stability of carbonates and nitrates increase down the grp because carbonates and nitrates have to be heated more strongly b4 they are completely decomposed.
Try to think this way: The carbonate ion has a small +2 charge into a small volume hence it has a high charge density. The distorting effect on a negative ion will increase.
D
www.chemguide.co.uk
contains notes classified according to our syllabus.
Thanks but why ''4-2x'' for the concentration of NO2?D
2NO2(g) --> 2NO(g) + O2(g)
initial conc= 4 : 0 : 0
equilibrium conc= (4-2x) : (2x) : (x)
It is given that equilibrium conc of O2 is 0.8, which means x = 0.8
equilibrium conc= (4-2(0.8)) : (2(0.8)) : (0.8)
equilibrium conc= 2.4 : 1.6 : 0.8
Kc = [NO]^2[O2] / [NO2]^2
Kc = (1.6)^2 (0.8) / (2.4)^2
It was initially 4 moles,Thanks but why ''4-2x'' for the concentration of NO2?
Hi,
I need help as i am not able to understand fully the markscheme answer.
Q. the trend of solubility of group2 sulfates.
Q. the trend of stability of carbonates and nitrates of group2 metals.
thankyou...
Given the equation for the complete combustion of ethylbenzene ...2C8H10(g)+ 21O2(g)==> 16CO2(g)+ 10H2O(l)what volume, in cm3, of ethylbenzene, is burned completely by 225cmof air? (3 sig fig answer, all gas volumes are measured at the same temperature and pressure, assume air is 21% oxygen)
SMI HELP MEEEEEEEEEEEE!!!!!!!!!!!!!!!!!!!!!!!!!1
Thankyou...Down Group 2 the solubility of sulfates decreases..This is because with increasing cation size both hydration enthalpy and lattice enthalpy decreases..
But the decrease in hydration enthalpy is more than the decrease in lattice enthalpy..the breaking of the lattice therefore becomes tougher down the group and hence they are more stable..
LE increases coz the intermolecular(vanderwaals)forces of attraction increases with increasing size and proton number!
The stability of carbonates and nitrates increases down the group..
ie..down the group cation size increases..
the charge density therefore decreases..
the polarizing ability of cation decreases..
less distortion of anion(carbonate/nitrate)
hence they are more stable down the group..
Don't confuse solubility and stability!!
Hope this helps!!)
16.Hey fellows need help with some paper 1 questionsHere are the links and questions.....Thanks.......
3.Hey fellows need help with some paper 1 questionsHere are the links and questions.....Thanks.......
3.
Answer is C
These are gases at RTP: O2, CO2, SO2
Since there is a 1:3 ratio with O2, O2 used is 30cm3
That means 60 - 30 = 30cm3 is left,
CO2 and SO2 are each produced 10 cm3
So,
Total volume of gases left = 30 cm3 O2 + 10 cm3 CO2 + 10 cm3 SO2
=50 cm3
23.
Answer is D
These are 9 possible products:
CH3 -CH2Br
CH2Br - CH2Br
CH2Br - CHBr2
CHBr2 - CHBr2
CHBr2 - CBr3
CBr3 - CBr3
CH3 - CHBr2
CH3 - CBr3
CH2Br - CBr3
Thats one difficult question though !
37.
Answer is A
1 is possible very simple !
2 is possible when two .C2H5 free radicals combine
3 is possible when the product from 2 combines with Cl. free radicals
They never said that they are reacting just 1 mol of ethane !
Hey fellows need help with some paper 1 questionsHere are the links and questions.....Thanks.......http://www.xtremepapers.com/CIE/International A And AS Level/9701 - Chemistry/9701_s05_qp_1.pdf Q13,18,38
berryllium (B)
shud be the answer for 13
going back on periodic table decreases the e.n value and going up increases ... net effect = 0
for 18,
it shud be "A"
because
NH4 ammonium has charge +1 , anything attached to it shud be of charge -1
and then count the number of C,N,H,O in the products and reactants
for 38,
i think it shud be B but i am not sure
For almost 10 years, the site XtremePapers has been trying very hard to serve its users.
However, we are now struggling to cover its operational costs due to unforeseen circumstances. If we helped you in any way, kindly contribute and be the part of this effort. No act of kindness, no matter how small, is ever wasted.
Click here to Donate Now