Hydraulic separation method is used for the concentration of which ore?

Cassiterite

Haematite

Calamine

Galena

A certain laser transition emits $$ 6.37 \times 10^{25} $$ quanta per second per square meter. The power output in joules per square meter per second would be ( $$ \lambda = 632.8 $$ nm)

$$ 5 \times 10^{5} Jm^{-2} sec ^{-1} $$

$$ 2 \times 10^{-3} Jm^{-2} sec ^{-1} $$

$$ 9.2 \times 10^{-3} Jm^{-2} sec ^{-1} $$

$$ 2 \times 10^{7} Jm^{-2} sec ^{-1} $$

A gas $$ X $$ bleaches the colour of flowers by reduction, while the other gas $$ Y $$ by oxidation. These two gases $$ X $$ and $$ Y $$ are respectively

$$ CO $$ and $$ CO_{2} $$

$$ NH_{3} $$ and $$ SO_{3} $$

$$ CO_{2} $$ and $$ Br_{2} $$

$$ SO_{2} $$ and $$ Cl_{2} $$

Diels-Alder reaction is used to synthesise a ring of

four carbon atoms

five carbon atoms

three carbon atoms

six carbon atoms

For the complex, $$ Ag^{+}+2NH_{3}\rightarrow [Ag(NH_{3})_{2}^{+}] $$ ,

$$ (\dfrac{dx}{dt})=2\times 10^{7}L^{2}mol^{-2}s^{-1}[Ag^{+}][NH_{3}]^{2} = 1\times 10^{-2}s^{-1}[Ag(NH_{3})_{2}^{+}] $$ .

Hence, the ratio of rate constants of the forward and backward reactions is

$$ 2\times 10^{7} $$ $$ L^{2} $$ $$ mol^{-2} $$

$$ 2\times 10^{9} $$ $$ L^{2} $$ $$ mol^{-2} $$

$$ 1\times 10^{-2} $$ $$ L^{2} $$ $$ mol^{-2} $$

$$ 0.5\times 10^{-9} $$ $$ L^{2} $$ $$ mol^{-2} $$

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