Answer:
a 1) XZ2
2) YZ
3) X2
b 1) Ionic bond
2) Ionic bond
3) covalent bond
c) ionic compounds has high melting and boiling point
ionic compounds can conduct electicity in aqueous form
covalent compounds have electrons shared between the atoms
covalent compounds have lower melting point compared to ionic compound
So you find the moles of the lead nitrate by doing mass/Mr so 25/331.2 which gives you 0.075
Due to stoichiometry in the reaction we see 1:2 ratio so we do 0.075x2 gives 0.15 moles of NaNO3
Then mass: moles x Mr so 0.15 x 85= 12.75g is your theoretical
So % yield is actual/ theoretical x 100
Therefore 6.0g/12.75 g x 100 = 47%
Not sure if it’s correct hope it helps!