The weight of oxalic acid that will be required to prepare a $1000 \ mL$ $(N / 20)$ solution is

Identify the correct statements:
$A$. Hydrated salts can be used as primary standard.
$B$. Primary standard should not undergo any reaction with air.
$C$. Reactions of primary standard with another substance should be instantaneous and stoichiometric.
$D$. Primary standard should not be soluble in water.
$E$. Primary standard should have low relative molar mass.
Choose the correct answer from the options given below :

$FeSO_4 \cdot (NH_4)_2SO_4 \cdot 6H_2O$ is called:

$K_2Cr_2O_7$ is preferred over $Na_2Cr_2O_7$ for use in volumetric analysis as a primary standard because

Which of the following cannot give iodometric titrations?

Which substance quickly absorbs oxygen?