The pairs are:
K, Kr - Same period
Be, Mg - Same group
Ni, Tc - Both are transition metals
B, Ge - Both are metaloids
Al, Pb - Both form inert oxides
A - 1 CH4+ 1 O2 = 1 CO2+2 H2
b - 2 Al+3 Cl2 = 2 AlCl3
c - 1 CH2O+ 1 H2 = 1 CH3OH
*The ones that have the coefficient of 1 you can leave blank but if you have to put a number just put 1
We are given with
136 g P4
excess oxygen
The complete combustion reaction is
P4 + 5O2 => 2P2O5
Converting the amount of P4 to moles
136/123.9 = 1.098 moles
Using stoichiometry
moles P2O5 = 1.098 x 2 = 2.195 moles P2O5
Answer:
They all can, but HCl would be the strongest conductors because they are strong acids/bases, meaning their ions dissociate at a faster rate in aqueous solution.
