the question says assume the valencies of hydrogen, nitrogen and carbon in the compounds are 1, 3 and 4 from this i must draw a structural formulae for hydrogen cyanide and cyanogen that are consistant with these valencies. please help
H : C::: N:
Does that work?
thanks but does that not then give N the valence of 4 in stead of three
No. The valence electrons are shared with C in a triple bond.
Mark--Those two unpaired electrons on the right hand side of the N atom don't count as a valence.
To draw the structural formula for hydrogen cyanide (HCN) and cyanogen (C2N2) with the given valencies, you need to consider the valence electrons of each element and their bonding patterns.
For hydrogen cyanide (HCN), hydrogen has a valency of 1, nitrogen has a valency of 3, and carbon has a valency of 4. This means that hydrogen can form one bond, nitrogen can form three bonds, and carbon can form four bonds.
To draw the structural formula for HCN, you start by placing the carbon atom in the center and connecting it to the nitrogen atom with a triple bond. Then, you connect the hydrogen atom to the carbon atom with a single bond. The structural formula for HCN is:
H-C≡N
For cyanogen (C2N2), you have two carbon atoms and two nitrogen atoms. Since each carbon atom can form four bonds and each nitrogen atom can form three, you can arrange the atoms in a linear fashion, alternating between carbon and nitrogen. The structural formula for C2N2 is:
C≡N-C≡N
By following these guidelines, you can draw the structural formulas for hydrogen cyanide and cyanogen consistent with the given valencies.