TS EAMCET 2018 :: Chemistry :: General questions

• Chemistry - General questions

 For a particular reaction , the rate constant becomes double on increasing temperature from  $27^{0} C$  to $37^{0}$C . Calculate the approximate activation energy

(in kcal  mol ^-1 R =2 cal mol^-1 K^-1)

Answer:

Explanation:

We know that

$\log\frac{k_{2}}{k_{1}}=\frac{E_{a}}{2.303 R}\times\frac{10}{93 \times1000}$

 $E_{a}=0.3010\times2\times93\times100\times2.303$

$E_{a}=5598.6cal\times2.303$

 $E_{a}=56\times2.303=12.89 kcal/mol$

Henry's law constant for $CO_{2}$ in water is 1.67 K bar at $25^{0}C$. The  quantity of $CO_{2}$  in 1000 mL of soda water  when packed under 5 bar $CO_{2}$ pressure at $25^{0} C$ is 

Answer:

Explanation:

We know that

$p= K_{B}\chi_{i}\Rightarrow p=K_{H}\times \frac{n_{1}}{n_{1}+n_{2}}$

 Given   is p= pressure (5 bar)

      $K_{H}$= Henery's  constant (1.67 K  bar)

$\chi_{1}$= mole fraction of solute   $CO_{2}$

 $\chi_{1}$= $\frac{n_{1}}{n_{1}+n_{2}} \Rightarrow =5=1.67 \times 10^{3} \times \frac{ H_{1}}{55.5}$

  $H_{1}= \frac{55.5 \times 5}{1.67 \times 10^{3}}=0.167 mol$

The IUPAC name of the following compound  is 

Answer:

Explanation:

IUPAC name

Amongest the chemical  reactions given below, the reactions with increasing entropy are 

(i)  $H_{2}O  \rightarrow  H_{2}O (g) $

(ii)   $C(s)+ CO_{2}(g) \rightarrow 2CO(g)$

(iii) $2H_{2}(g)+O_{2}(g)\rightarrow    2H_{2}O(l)$

(iv)   $ N_{2} (g)+O_{2}(g) \rightarrow   $  Mixture of $N_{2}$ and $O_{2}$

Answer:

Explanation:

(i)  $H_{2}O  \rightleftharpoons  H_{2}O (g) $  system is changed so , entropy is maximum

(ii)   $C(s)+ CO_{2}(g) \rightarrow 2CO(g)$ in  this system product has more number of gaseous moles. Thus , entropy increases

(iii) $2H_{2}(g)+O_{2}(g)\rightarrow    2H_{2}O(l)$  gasesous  system is converted into liquid system , So, entropy decreases

(iv)   $ N_{2} (g)+O_{2}(g) \rightarrow   $  Mixture of $N_{2}$ and $O_{2}$   mixture of $N_{2}$ and $O_{2}$  , on mixing total gaseous volume  increases in comparison to their individual volume hence entropy increases

 The symbol of an element is Une. Its  atomic  number is 

Answer:

Explanation:

Une is a synthetic chemical element with the symbol Mt( Meitnerium) and its atomic number is 109

 Because  in one , U= un, ie 1, n=nil , ie, 0

 e= enn, i.e ,9

Its comes under d-block trans actinide elements. It is an extremely radioactive synthetic element that is not found in nature and synthesised in the laboratory

• Chemistry - General questions