Class 12th

Hybridization of P in PF₅ is sp³d, so value of y = 1.

Work function,  ${?}_0=6.63*10^{-19}J$

Threshold wavelength ${\lambda }_0=?$

Using ; ${?}_0=\frac{hc}{{\lambda }_0}$

${\lambda }_0=\frac{hc}{{?}_0}$

= 300 * 109 m = 300 nm

$Mn{O}_2+4HCl\to MnC{l}_2+C{l}_2+2H_{2}O$  

$\begin{array}{l}C{l}_2+2Kl\to 2KCl+I_2\\ I_2+2N{a}_2{S}_2{O}_3\to 2Nal+N{a}_2{S}_4{O}_6\end{array}$               

Here, meq of MnO₂ = meq of Na₂S₄O₆

$\frac{w}{E}*1000=M*n-factor*V$                              

$\frac{w}{87/2}*1000=0.1*1*60$                              

Mass of MnO₂ in sample = 0.261 g

Percentage of MnO₂ in sample =   $\frac{0.261}{2}*100$

= 13.05%

$\underset{\begin{array}{l}Sodiumextract\\ ofsulphur\end{array}}{N{a}_{2}S}+N{a}_2\underset{Sodiumnitroprusside}{\left[Fe{\left(CN\right)}_{5}NO\right]}\to N{a}_4\underset{violet/purple}{\left[Fe{\left(CN\right)}_{5}NOS\right]}$

$\alpha -$ Helix (2°) structure of protein is stabilized by intermolecular H-bonding.

Copolymer is the polymer formed by two or more monomers having multiple bonds.

Buna – S, PHBV and butadiene – styrene are copolymers. Neoprene is homopolymer.

$R-N{H}_2\underset{273K}{\overset{HN{O}_2\left(aq.\right)}{\to }}R-\stackrel{\oplus }{N_2}\underset{298K}{\overset{H_{2}O/-N_2\uparrow }{\to }}R-OH$

1° aliphatic amine           Diazonium salt                Alcohol

In thin layer chromatography, the spots of colourless compounds, which are invisible to eyes can be detected by putting the plate under UV light.

Another detection technique is to place the plate in a covered jar containing I₂ (s). Sometimes an appropriate reagent may also be sprayed on the plate, ninhydrin in case of amino acids

DDT, organophosphates and dieldrin are pesticides.