Question

solve the question no. 19

Answer 1

x is ethanol
y is ethene
z is ethane

Answer 2

x=ethanol CH3-CH2OH
y=ethane CH2 = CH2+H2O

    CH3-CH2OH   →   CH2 = CH2+H2O (excess con H2SO4)
(note that "= "is the double bond)
 heating thane at 443 k with excess con H2SO4 result in the dehydration of ethanol to give ethane
 the reaction is: C₂H₆ + 2O₂ → 2CO₂ + 3H₂O So, this makes Z an ethane. 
compound y will be alkane 
     z=CH3-CH3
C₂H₄ + H₂→C₂H₆(nickel catalyst (H2))

hope this will help you