Which biopolymer was first used for post-operative stitches?

In the modern industrial method for the production of ethanol, hydration of ethene is carried out in the presence of which substance?

On dropping a small piece of sodium in a test tube containing carbon compound $X$ with molecular formula $C_{2}H_{6}O$,a brisk effervescence is observed and a gas $Y$ is produced. On bringing a burning splinter at the mouth of the test tube,the gas evolved burns with a pop sound. Identify $X$ and $Y$. Also,write the chemical equation for the reaction. Write the name and structure of the product formed when you heat $X$ with excess concentrated sulphuric acid.

Write the chemical formula and draw the electron dot structure of carbon tetrachloride.

$(i)$ How will you bring about the following reactions? Write the concerned chemical equations:
$(a)$ Ethanol to Ethene.
$(b)$ Ethanol to Ethanoic acid.

Which aldehyde compound does not contain an alkyl group?