- Messages
- 169
- Reaction score
- 117
- Points
- 38
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s10_qp_12.pdf q2,3,4,6,11 actuallly most of the questions of the ppr bcz this ppr is kinda hard for me
q2: phosphorus is well know ...it has 3 unpaired electrons in its p sub shell : 1s2 2s2 2p6 3s2 3p3
q3: write down the electronic configuration of the three elements
q4:
when bonds are broken energy is absorbed ( + sign) ...when bonds are formed energy is released (- sign)
q6 :
in NH4NO3 ...consider NH4+ .... +4 (hydrogen) + N = +1
so N= -3 in NO3- ... 3* -2 + N = -1 so N= +5
in N2O each N has a ox.state of +1
now calculate change from one nitrogen from NH4 to N in N2O = -3-1 = -4
and change from NO3 to another N in N2O is = 5-1 = +4
hence D
q 11 Haber process is well known as well ....as pressure increases yield should increase since forward reaction has fewer no. of molecules ...and since the reaction is exothermic increasing the temperature favors backward reaction decreasing the yield of ammonia