In a first order reaction,the concentration of reactant decreases from 400 moles lit $^{-1}$ to 50 moles lit ${ }^{-1}$ in $7 \cdot 5 \times 10^3 \mathrm{~s}$ .The rate constant of the reaction is(approximately)
$1 \times 10^{-2} \mathrm{~s}^{-1}$
$2.5 \times 10^{-3} \mathrm{~s}^{-1}$
$1 \times 10^{-5} \mathrm{~s}^{-1}$
$2.77 \times 10^{-4} \mathrm{~s}^{-1}$
In the following reaction sequence, the product Y is
$$ \mathrm{Br}\left(\mathrm{CH}_2\right)_{12}-\mathrm{C} \equiv \mathrm{CH} \xrightarrow{\mathrm{NaNH}_2} \mathrm{X} \xrightarrow[\text { catalyst }]{\mathrm{H}_2, \text { Lindler }} \mathrm{Y} $$


$$ \mathrm{Br}\left(\mathrm{CH}_2\right)_{12}-\mathrm{CH}=\mathrm{CH}_2 $$

The mass of an electron is $9 \cdot 1 \times 10^{-31} \mathrm{~kg}$ .If its K .E.is $3 \cdot 0 \times 10^{-25} \mathrm{~J}$ ,its wavelength is(approximately)
250 nm
400 nm
990 nm
850 nm
The calculated magnetic moment for low spin $[\operatorname{Ru}(E D T A)]^{-}$is
2.73 BM
1.73 BM
3.23 BM
0.00 BM
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