Class 12th

This is a  Fill in the Blanks Type Questions as classified in NCERT Exemplar

Sol:

$\begin{array}{l}Giventhat:P\left(A\right)=p,P\left(B\right)=\frac{1}{3}andP\left(A\cup B\right)=\frac{5}{9}\\ P\left(A/B\right)=\frac{P\left(A\cap B\right)}{P\left(B\right)}=p\Rightarrow P\left(A\cap B\right)=p.P\left(B\right)=p.\frac{1}{3}\\ andP\left(A\cup B\right)=P\left(A\right)+P\left(B\right)-P\left(A\cap B\right)\\ \frac{5}{9}=p+\frac{1}{3}-\frac{p}{3}\Rightarrow \frac{5}{9}-\frac{1}{3}=\frac{2p}{3}\Rightarrow \frac{2}{9}=\frac{2p}{3}\Rightarrow p=\frac{1}{3}\\ Hence,pisequalto\frac{1}{3}.\end{array}$

This is a multiple choice answer as classified in NCERT Exemplar

Correct option is (iii)

Hydrogen iodide is a more powerful reducing agent than sulphuric acid, it reduces the amount of iodine in the solution from H₂SO₄ to SO₂ and HI to I₂

When chloride salts are treated with sulfuric acid,  HCl gas is formed, which produces a colourless gas.

NaCl + H₂SO₄→HCl + Na₂SO₄

Violet fumes are produced during the reaction due to the creation of iodine (I₂) gas.

2NaI + H₂SO₄→Na₂SO₄ + 2HI 2H₂O + SO₂ + I₂

This is a True or False Type Questions as classified in NCERT Exemplar

Sol:$\begin{array}{l}{\mathrm{}}^{}\end{array}$

$\begin{array}{l}True\\ SinceP\left(atleasttwoofA,BandCoccur\right)\\ =p*p*\left(1-p\right)+\left(1-p\right).p.p+p\left(1-p\right).p+p.p.p\\ =3p^2\left(1-p\right)+p^3=3p^2-3p^3+p^3=3p^2-2p^3\end{array}$

This is a True or False Type Questions as classified in NCERT Exemplar

Sol:  $False\left[?P\left(B/A\right)=\frac{P\left(A\cap B\right)}{P\left(A\right)}=\frac{P\left(A\right)+P\left(B\right)-P\left(A\cup B\right)}{P\left(A\right)}>\frac{1-P\left(A\cup B\right)}{P\left(A\right)}\right]$

This is a short answer type question as classified in NCERT Exemplar

The following reaction with silver nitrate demonstrates phosphinic acid reducing behaviour:

4AgNO₃ + 2H₂O + H₃PO₂→4Ag + 4HNO₃ + H₃PO₄

This is a True or False Type Questions as classified in NCERT Exemplar

Sol:  $True$ $$

This is a short answer type question as classified in NCERT Exemplar

PCl₅ + 2Ag→2AgCl + PCl₃

AgCl + 2NH₃ (aq)→ [Ag (NH₃)₂] + Cl^- 

This is a True or False Type Questions as classified in NCERT Exemplar

Sol:  $True\left[?P\left(A\text{'}\cup B\right)=1-P\left(A\cap B\text{'}\right)=1-P\left(A\right).P\left(B\text{'}\right)\right]$ $$

This is a short answer type question as classified in NCERT Exemplar

When nitric acid is mixed with copper metal, it produces distinct oxidation products.

3Cu + 8HNO₃ (dil.)→3Cu (NO₃)₂ + 2NO + 4H₂O

Cu + 4HNO₃ (Conc)→3Cu (NO₃)₂ + 2NO₂ + 2H₂O

This is a True or False Type Questions as classified in NCERT Exemplar

Sol:  $True\left[?E\left(X\right)={\displaystyle \sum _{}^{}{X}_{i}P\left(X_i\right)}\right]$ $$