Which of the following reagents cannot, be used to oxidise primary alcohols to aldehydes?
(a) \(CrO_3\) in anhydrous medium.
(b) \(KMnO_4\) in acidic medium.
(c) Pyridinium chlorochromate.
(d) Heat in the presence of Cu at 573 K.
(a) \(CrO_3\) in anhydrous medium.
(b) \(KMnO_4\) in acidic medium.
(c) Pyridinium chlorochromate.
(d) Heat in the presence of Cu at 573 K.
(b) \(KMnO_4\) in acidic medium.
Which of the following alcohols gives 2-butenc on dehydration by conc.\(H_2\)\(SO_4\)?
(a) 2-methyl propene-2-ol.
(b) 2-methyl 1 -propanol.
(c) Butane-2-ol.
(d) Butane 1-ol.
Which of the following alcohols will give the most stable carbocation during dehydration?
(a) 2-methyl-1-propanol.
(b) 2-methyl-2-propanol.
(c) 1-Butanol.
(d) 2-Butanol.
1-Phenylethanol can be prepared by the reaction of benzaldehyde with
(a) methyl bromide.
(b) ethyl iodide and magnesium.
(c) methyl iodide and magnesium.
(d) methyl bromide and aluminium bromide.
Order of esterification of alcohols are
(a) 3° > 1° > 2°.
(b) 2°> 3° > 1°.
(c) 1 ° > 2° > 3°.
(d) None of these.
What happens when tertiary butyl alcohol is passed over heated copper at 300°C?
(a) Secondary butyl alcohol is formed.
(b) 2-methylpropene is formed.
(c) 1-butene is formed.
(d) Butanol is formed.
Propanone on reaction with alkyl magnesium bromide followed by hydrolysis will produce
(a) primary alcohol
(b) secondary alcohol
(c) tertiary alcohol
(d) carboxylic acid
The ionisation enthalpy of the group 15 elements is much greater than that of group 14 elements in the corresponding periods. Which is the most suitable reason?
a) more effective nuclear charge
b) presence of stable half-filled electronic configuration
c) smaller size
d) high electronegativity
Which is the correct statement?
a) valence shell electronic configuration of group 16 elements is \(ns^1\)\(np^4\).
b) the elements of group 16 have lower ionisation enthalpy values compared to those of Group 15 in the corresponding periods.
c) Oxygen atom has more negative electron gain enthalpy than sulphur.
d) oxygen has the highest electronegativity value amongst the elements.
Looking at the setup of an electrochemical cell, what happens when \(E_{ext}\) > 1.1 V
Highest oxidation state of manganese in fluoride is +4 (MnF₄) but highest oxidation state in oxides is +7 (Mn₂O₇) because
(a) fluorine is more electronegative than oxygen.
(b) fluorine does not possess d-orbitals.
(c) fluorine stabilises lower oxidation state.
(d) in covalent compounds fluorine can formsingle bond only while oxygen forms double bond.
What happens when tertiary butyl alcohol is passed over heated copper at 300°C?
(a) Secondary butyl alcohol is formed.
(b) 2-methylpropene is formed.
(c) 1-butene is formed.
(d) Butanol is formed.
Which of the following is a network solid?
(A) (solid)
(B)
(C) Diamond
(D) (ice)
The correct order of the packing efficiency in different types of unit cells is ________.
(A) fcc < bcc < simple cubic
(B) fcc > bcc > simple cubic
(C) fcc < bcc > simple cubic
(D) bcc < fcc = simple cubic