Aspirin is chemically known as:

Which compound is used as a food preservative?

What is tincture of iodine? What is its use?

Which of the following compounds is an example of a hypnotic drug?

Given below are two statements,one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: Butylated hydroxy anisole when added to butter increases its shelf life.
Reason $R$: Butylated hydroxy anisole is more reactive towards oxygen than food.
In the light of the above statements,choose the most appropriate answer from the options given below:

‘Placebo’ is often given to patients. It is