Magnifying power of a simple microscope is (when final image is formed at $D = 25 \ cm$ from eye)

Which of the following pairs of substances illustrates the law of multiple proportions?

Consider the following reaction,
$C_2H_5Cl + AgCN \xrightarrow{EtOH / H_2O} \underline{X} \text{ (major)}$
Which one of the following statements is true for $\underline{X}$?
$(I)$ It gives propionic acid on hydrolysis
$(II)$ It has an ester functional group
$(III)$ It has a nitrogen linked to ethyl carbon
$(IV)$ It has a cyanide group

........ of a reaction cannot be determined experimentally.

The formula for exponential population growth is

Which of the following is the strongest reducing agent?