$1 \, g$ of hydrogen combines with $80 \, g$ of bromine,and $1 \, g$ of calcium combines with $4 \, g$ of bromine. What is the equivalent weight of calcium?

Calculate the average atomic mass of hydrogen using the following data:

Isotope	$\%$ Natural abundance	Molar mass
$^1H$	$99.985$	$1$
$^2H$	$0.015$	$2$

The modern atomic weight scale is based on

Complete reaction of $2.0 \, g$ of calcium (at. wt. $= 40$) with excess $HCl$ produces $1.125 \, L$ of $H_2$ gas. Complete reaction of the same quantity of another metal $M$ with excess $HCl$ produces $1.85 \, L$ of $H_2$ gas under identical conditions. The equivalent weight of $M$ is closest to

The equivalent weight of phosphoric acid $(H_3PO_4)$ in the reaction $NaOH + H_3PO_4 \to NaH_2PO_4 + H_2O$ is

In order to prepare one litre of a $1 \ N$ (normal) solution of $KMnO_4$,how many grams of $KMnO_4$ are required if the solution is used in an acidic medium for oxidation?