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What happens to the volatility of halogens and of hydrogen halides as we go down the group??!!!
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SiCl4 is a covalent compound. The bonding in AlCl3 is more covalent than it is ionic. When the question asks which is ionic which SOME covalent character it is asking about compound where the main bond is ionic.
The question says ionic with some covalent character. this only happens when
- the charge on the cation is large ( Mg > Na )- the cation is small ( Mg < Na )- the size of the anion is largesince both anion are the same, and Mg is smaller in size and has a greater charge, it has a higher covalent character then Na.The main bonding in MgCl2 and NaCl are ionic bond and MgCl2 has more covalent tendency so the answer is B.
What happens to the volatility of halogens and of hydrogen halides as we go down the group??!!!
yesvolatility decreases down the group coz vanderwaals forces increases as we move down the group (moving down the group the number of electrons increases) so due to these attracted forces volatility trend decreases moving down the group ..........
stability of hydrogen halides decreases down the group ........as we move down the group the bond lenght increases means bond energy decreases therefore less energy is needed to break the bonds so thermal stability is decreased
*Al2O6 not Al3O6AlCl3 DOESNOT show Ionic Character , it is an Exception , AlCl3 further Form a Dimer with Al3Cl6
Na is Highly Electropositive in nature ( tendency to give electron , because of being in group 1 and Period 3 ) while Chorine is Highly Electronegative so it is Ionic
SICl4 is purely covalent
and justification for MgCl2 is correct ..
Ionic or Covalent bonding depends on difference in electronegativity between two BONDED atoms
If the Difference is less greater than 1.7 than it is Ionic else covalent ..
flourine have highest electronagativity of 4
In this question and in similar questions you should consider the outer most shell, ONLY.http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Chemistry (0620)/0620_s08_qp_1.pdf
Question 9
Pls can some one explain this?
In this question and in similar questions you should consider the outer most shell, ONLY.
Now see in P the outer most electron has 6 electrons
And in Q it has 1
As mentioned in question they form Ionic compound.
So transfer of electron occur.
And this is obviously from Q to P .
P needs 2 more electrons to form full outershell ( tht is 8 in total)
And Q can only give 1
thus, we need 2 from Q to satisfy one P
So the formula wilL be
PQ2 which is the answer A
for q8 mj2010when u get the answers to the rest of the questions... plz tag me 2 bcuz they were mighty DIFICULT O__O x.x
For question 2,Please help with question number 2 and 10 with details. http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s06_qp_1.pdf
when u get the answers to the rest of the questions... plz tag me 2 bcuz they were mighty DIFICULT O__O x.x
for w10 q7can any 1 give explanations for the following mcqs:
m/j 2010 mcq 8 , 12:
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s10_qp_12.pdf
o/n 2010 mcq 7 , 12, 13 ,18, 40 :
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w10_qp_12.pdf
o/n 2011 mcq 30 :
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w11_qp_12.pdf
m/j 2011 mcq 40 , 23 , 11:
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s11_qp_12.pdf
Thanks in advance.
can any 1 give explanations for the following mcqs:
m/j 2010 mcq 8 , 12:
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s10_qp_12.pdf
o/n 2010 mcq 7 , 12, 13 ,18, 40 :
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w10_qp_12.pdf
o/n 2011 mcq 30 :
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w11_qp_12.pdf
m/j 2011 mcq 40 , 23 , 11:
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s11_qp_12.pdf
Thanks in advance.
for W11 q30when u get the answers to the rest of the questions... plz tag me 2 bcuz they were mighty DIFICULT O__O x.x
for q11 s11can any 1 give explanations for the following mcqs:
m/j 2010 mcq 8 , 12:
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s10_qp_12.pdf
o/n 2010 mcq 7 , 12, 13 ,18, 40 :
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w10_qp_12.pdf
o/n 2011 mcq 30 :
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w11_qp_12.pdf
m/j 2011 mcq 40 , 23 , 11:
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s11_qp_12.pdf
Thanks in advance.
Ca + 2CH3COOH ----> Ca2+ + 2CH3COO- + H2.for q11 s11
Experimentally, moles of C present = 3x10^-3
Molar mass of AlxCy = 27x + 12y
Moles of AlxCy present = sample mass / molar mass = 0.144 / (27x + 12y)
look if we want to find the number moles of element in a compound we multiply the number of moles of that compound and number of moles of that element present in it for example
H20
if i have 2 moles of h20 how many moles of hydrogen are there simple 2*2
so
By stoichiometry, moles of C present = moles of (AlxCy) x = y (0.144 / (27x + 12y))
Which can be equated to 3x10^-3 found earlier.
Simplifying the mathematical expression, we obtain x/y = 4/3.
Hence the answer is C, aluminium carbide.
for q23
In chemistry, mole fraction x is a way of expressing the composition of a mixture hence the mole fractions are
50% or 1/2 are ethene,
25% or 1/4 are methane,
and 25% or 1/4 are propene.
we need whole number so multiply by 4
we get 200 percent and 100 percent 100percent respectively.
this means 2 moles of ethene and 1,1 moles of methane and propene
for 40
you bettt it waas!! it made freakin mind mince out of my head :O
thanks a lot snowbrood and daredevilsnowbrood u r a genius!!Ca + 2CH3COOH ----> Ca2+ + 2CH3COO- + H2.
as u know that ch3coo- u need two ch3coo to balance Ca
so u get 2*(CH3COO)Ca
c4h6O4
use first equation to find the empirical formula for other two equations u will find only first one is correct.
hehe thanks i am glad that i could helpthanks a lot snowbrood and daredevilsnowbrood u r a genius!!
Sorry actually i dont know how 2 tag.
can u tell how 2 tag , plz.hehe thanks i am glad that i could help
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