Oxygen is a Group 16 element. Fig. 2.1 shows the boiling points of $$\(\mathrm{H}_{2} \mathrm{O}\)$$ and other Group 16 hydrides. Fig. 2.1 (i) Explain the trend in the boiling points of the Group 16 hydrides $$\(\mathrm{H}_{2} \mathrm{~S}\)$$ to $$\(\mathrm{H}_{2} \mathrm{Te}\)$$. ....................................................................................................................................... . ....................................................................................................................................... . ....................................................................................................................................... . ................................................................................................................................. (ii) Explain why the boiling point of $$\(\mathrm{H}_{2} \mathrm{O}\)$$ is much higher than that of $$\(\mathrm{H}_{2} \mathrm{~S}\)$$. ....................................................................................................................................... . ....................................................................................................................................... . .................................................................................................................................
Exam No：9701_w24_qp_22 Year：2024 Question No：2(c)
Answer:
Knowledge points:
16.1.1.1 electrophilic addition of steam to an alkene, catalyst
16.1.1.2 reaction of alkenes with cold dilute acidified potassium manganate(VII) to form a diol
16.1.1.3 substitution of a halogenoalkane using NaOH(aq) and heat
16.1.1.4 reduction of an aldehyde or ketone using
16.1.1.5 reduction of a carboxylic acid using
16.1.1.6 hydrolysis of an ester using dilute acid or dilute alkali and heat
16.1.2.1 the reaction with oxygen (combustion)
16.1.2.2 substitution to halogenoalkanes
16.1.2.3 the reaction with Na(s)
16.1.2.4 oxidation with acidified or acidified to:
16.1.2.5 carbonyl compounds by distillation
16.1.2.6 carboxylic acids by refluxing (primary alcohols give aldehydes which can be further oxidised to carboxylic acids, secondary alcohols give ketones, tertiary alcohols cannot be oxidised)
16.1.2.7 dehydration to an alkene, by using a heated catalyst, e.g. or a concentrated acid
16.1.2.8 formation of esters by reaction with carboxylic acids and concentrated or as catalyst as exemplified by ethanol
16.1.3.1 classify alcohols as primary, secondary and tertiary alcohols, to include examples with more than one alcohol group
16.1.3.2 state characteristic distinguishing reactions, e.g. mild oxidation with acidified K2Cr2O7, colour change from orange to green
16.1.4 deduce the presence of a group in an alcohol, , from its reaction with alkaline (aq) to form a yellow precipitate of tri-iodomethane and an ion,
16.1.5 explain the acidity of alcohols compared with water
Solution:
Download APP for more features
1. Tons of answers.
2. Smarter Al tools enhance your learning journey.
IOS
Download
Download
Android
Download
Download
Google Play
Download
Download