Exercise

Two salts X and Y are taken in two test tubes A and B, respectively and subjected to heating. Water is added to two test tubes, in case of A salt regains its original colour and in case of B water starts boiling. Then, X and Y may be, respectively: 

Heating an alcohol with concentrated sulphuric acid results in the dehydration of the alcohol to give the alkene as shown by the reaction of ethanol to give ethene.

${\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{OH}\stackrel{\mathrm{Hot} \mathrm{conc}.\mathrm{sulphuric} \mathrm{acid}}{\to }{\mathrm{CH}}_2={\mathrm{CH}}_2$

Pramila heated $2$-butanol (shown below) with concentrated sulphuric acid.

Write the structural formulae of all the possible products of the reaction.

Polythene is a plastic made from ethene(${\mathrm{CH}}_2={\mathrm{CH}}_2$). When ethene is subjected to high pressure and moderately  high temperatures, ethene molecules react with each other to form large molecules hundreds of times bigger, forming the plastic.
Which property of carbon atoms is instrumental in the formation of polythene?

The picture shows the incomplete chain structure of a carbon compound. The second carbon atom has two free electrons.

How many oxygen atoms can combine with the second carbon atom to complete the structure?

Which of these molecules contains a double bond?

A part of a homologous series is shown below.
${\mathrm{C}}_3{\mathrm{H}}_4, {\mathrm{C}}_4{\mathrm{H}}_6, {\mathrm{C}}_5{\mathrm{H}}_8$

Which of these compounds is a part of the series shown above?

The picture shows the bonds between atoms in two allotropes of carbon.

Which allotrope is harder? Explain your answer.

Dipti has three flasks containing dilute hydrochloric acid, dilute sulphuric acid and dilute sodium hydroxide respectively. The flasks are not labelled, and she does not have any pH indicator. 
(a) Which of the solutions will she be able to identify just by making mixtures of pairs of the substances. 
(b) What observation will help her to make this identification?