Order of a reaction can have

For the following reaction: $NO_2(g) + CO(g) \to NO(g) + CO_2(g)$, the rate law is: Rate $= k \,[NO_2]^2$. If $0.1\,mole$ of gaseous carbon monoxide is added at constant temperature to the reaction mixture which of the following statements is true?

The reaction $2{H_2}{O_2} \to 2{H_2}O + {O_2}$ is a

The possible mechanism for the reaction

$2NO + Br \to 2NOBr$ is

$NO + Br_2 \rightleftharpoons NOBr_2$ (Fast)

$NOBr_2 + NO \to 2NOBr$ (Slow)

The rate law expression is

For the reaction, $2A + B\,\to $ products , when the concentrations of $A$ and $B$ both were doubled, the rate of the reaction increased from $0.3\,mol\,L^{-1}\,s^{-1}$ to $2.4 \,mol\,L^{-1}\,s^{-1}.$ When the concentration of $A$ alone is doubled, the rate increased from $0.3\,mol\,L^{-1}\,s^{-1}$ to $0.6\,mol\,L^{-1}\,s^{-1}.$ Which one of the following statements is correct?

For the decomposition of azoisopropane to hexane and nitrogen at $543$ $K ,$ the following data are obtained.

Calculate the rate constant.