What are X, Y, Z in the following reactions ?
`{:(" "OH),(" |"),(CH_(3)-CH-CH_(3) overset(x)rarrCH_(3)-CH=CH_(2)+H_(2)O):}`
`CH_(3)-CH_(2)-OH overset(Y)rarr CH_(2)=CH_(2) + H_(2)O`
`{:(" "CH_(3)),(" |"),(CH_(3)-C-OH overset(Z)rarr CH_(3)-C=CH_(2)+H_(2)O),(" |"" |"),(" "CH_(3)" "CH_(3)):}`

Options

A. `{:(" "X," "Y," "Z),(H_(2)SO_(4)","443K,85% H_(3)PO_(4)"," 440 K, 20% H_(3)PO_(4)"," 358 K):}`
B. `{:(" "X," "Y," "Z),(85% H_(3)PO_(4)"," 440 K,H_(2)SO_(4)","443K, 20% H_(3)PO_(4)"," 358 K):}`
C. `{:(" "X," "Y," "Z),(20% H_(3)PO_(4)"," 358 K,H_(2)SO_(4)","443K,85% H_(3)PO_(4)"," 440 K ):}`
D. `{:(" "X," "Y," "Z),(H_(2)SO_(4)","443K,20% H_(3)PO_(4)"," 358K ,85% H_(3)PO_(4)"," 440 K ):}`

Answer

B

Explanation

`{:(" "OH),(" |"),(CH_(3)-CH-CH_(3) underset(440 K)overset(85 % H_(3)PO_(4)(X))rarr CH_(3) - CH = CH_(2)+ H_(2)O):}`
`CH_(3)CH_(2)OH underset(443 K)overset(H_(2)SO_(4)(Y))rarr CH_(2) = CH_(2) + H_(2)O`
`{:(" "CH_(3)),(" |"),(CH_(3)-C-OH underset(358K)overset(20% H_(3)PO_(2)(Z))rarrCH_(3)-C=CH_(2)+H_(2)O),(" |"" |"),(" "CH_(3)" "CH_(3)):}`
These reactions are known as dehydration reaction where `H_(3)PO_(4)` and `H_(2)S_(4)` are dehydrating agents. Ethanol undergo dehydration by heating with conc. `H_(2)SO_(4)` at 443 K whereas `2^(@)` alcohols by 85% `H_(2)PO_(4)` at 440 K and `3^(@)` alcohols by 20% `H_(3)PO_(4)` at 358 K.