The pair of amphoteric hydroxides is
Al(OH)3, LiOH
Be(OH)2, Mg(OH)2
B(OH)3, Be(OH)2
Be(OH)2, Zn(OH)2
Which of the following chemicals are used to manufacture methyl isocyanate that caused "Bhopal Tragedy"?
(i) methylamine
(ii) phosgene
(iii) phosphine
(iv) dimethylamine
(i) and (iii)
(iii) and (iv)
(i) and (ii)
(ii) and (iv)
Among the following the most stable compound is
cis-1,2-cyclohexanediol
trans-1,2-cyclohexanediol
cis-1,3-cyclohexanadiol
trans-1,3-cyclohexanediol.
D.
trans-1,3-cyclohexanediol.
Trans configuration is more stable than cis configuration because in cis-configuration the H groups are thrown closely enough together to cause crowding or repulsion. Again between 1,2-and 1.3 configurations, in 1-3, the OH groups are placed further appart to minimise the repulsion. Hence, more stable is 1,3-configuration.
3-Phenylpropene on reaction with HBr gives (as a major product)
C6H5CH2(Br)CH3
C6H5CH(Br)CH2CH3
C6H5CH2CH2CH2Br
C6H5CH(Br)CH=CH2
Assertion : Borax bead test is not suitable for Al(III).
Reason : Al2O3 is insoluble in water.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Assertion : Ozone is a powerful oxidising agent in comparison to O2.
Reason : Ozone is diamagnetic but O2 is paramagnetic.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.