What is the effect of adding $Kr$ (krypton) gas at equilibrium while keeping the volume of the system constant?

Consider the following equation:
$2 SO_{2(g)} + O_{2(g)} \rightleftharpoons 2 SO_{3(g)}, \Delta H = -190 \ kJ$
The number of factors which will increase the yield of $SO_3$ at equilibrium from the following is $.............$.
$A.$ Increasing temperature
$B.$ Increasing pressure
$C.$ Adding more $SO_2$
$D.$ Adding more $O_2$
$E.$ Addition of catalyst

When a sample of $NO_2$ is placed in a container,this equilibrium is rapidly established: $2NO_{2(g)} \rightleftharpoons N_2O_{4(g)}$. If this equilibrium mixture is a darker colour at high temperatures and at low pressure,which of these statements about the reaction is true?

The effect of increasing the pressure on the equilibrium $2A + 3B \rightleftharpoons 3A + 2B$ is

The reaction $CaCO_3 \rightleftharpoons CaO + CO_{2(g)}$ goes to completion in a lime kiln because:

Under what conditions of temperature and pressure will the formation of atomic hydrogen from molecular hydrogen be favoured most?