What is used to preserve the dead bodies of animals?

Which substance,when added as an adulterant to ethanol used as an intoxicating drink,causes a person to lose their vision?

What is the molecular formula of methanol?

What is the general formula for the corresponding alcohol of an alkane?

$(i)$ What is vinegar? State its one use.
$(ii)$ Which gas is produced when dilute ethanoic acid is added to sodium bicarbonate? How will you test the presence of this gas?

$A$ mixture of oxygen and ethyne is burnt for welding. Can you tell why a mixture of ethyne and air is not used?