MCQ
Most abundant element on earth is
- ✓$O$
- B$S$
- C$Se$
- D$Te$
The amount of hydrogen on earth's crust is $0.15\, \%$.
The amount of nitrogen on the earth's crust is $0.002\, \%$.
The amount of silicon on earth's crust is $30\, \%$.
Hence, oxygen is the most abundant element on earth's crust.
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Sum of the number of methylene groups $\left(- CH _2-\right.$ ) and oxygen atoms in $R$ is. . . .
take place in two steps :
$(a)$ $Br^{-} + H^{+} + H_2O_2 \xrightarrow{{slow}} HOBr + H_2O$
$(b)$ $HOBr + Br^{-} + H^{+} \xrightarrow{{fast}} H_2O + Br_2$
The order of the reaction is