Salt<span> consists of positive sodium </span>ions<span> </span><span> and negative chloride </span>ions<span> </span>
Answer:
Various limitations of Mendeleev's periodic table are:-
Position of hydrogen - he couldn't assign a correct position to hydrogen as it showed properties of both alkali and halogens .
Position of isotopes - he considered that the properties of elements are a function of their atomic masses. Hence isotopes of a same element couldn't be placed.
In the d-block , elements with lower atomic number were placed before higher atomic number.
Explanation:
<span>Mass of the solution = 0.17m
Kb for C6H5NH2 = 3.8 x 10^-10
We know Ka for C6H5NH2 = 1.78x10^-11
We have Kw = Ka x Kb => Ka = Kw / Kb
=> (C2H5NH2)(H3O^+)/(C2H5NH3^+) => 1.78x10^-11 = K^2 / 0.17
K^2 = 3 x 10^-12 => K = 1.73 x 10^-6.
pH = -log(Kw(H3O^+)) = -log(1.73 x 10^-6) = 5.76</span>
Answer : The correct option is, (C) 1.7
Explanation :
First we have to calculate the moles of
and
.
![\text{Moles of }Ca(OH)_2=\text{Concentration of }Ca(OH)_2\times \text{Volume of solution}=0.10M\times 0.1L=0.01mole](https://tex.z-dn.net/?f=%5Ctext%7BMoles%20of%20%7DCa%28OH%29_2%3D%5Ctext%7BConcentration%20of%20%7DCa%28OH%29_2%5Ctimes%20%5Ctext%7BVolume%20of%20solution%7D%3D0.10M%5Ctimes%200.1L%3D0.01mole)
![\text{Moles of }HBr=\text{Concentration of }HBr\times \text{Volume of solution}=0.10M\times 0.3L=0.03mole](https://tex.z-dn.net/?f=%5Ctext%7BMoles%20of%20%7DHBr%3D%5Ctext%7BConcentration%20of%20%7DHBr%5Ctimes%20%5Ctext%7BVolume%20of%20solution%7D%3D0.10M%5Ctimes%200.3L%3D0.03mole)
The balanced chemical reaction will be:
![Ca(OH)_2+2HBr\rightleftharpoons CaBr_2+2H_2O](https://tex.z-dn.net/?f=Ca%28OH%29_2%2B2HBr%5Crightleftharpoons%20CaBr_2%2B2H_2O)
0.01 mole of
dissociate to give 0.01 mole of
ion and 0.02 mole of
ion
and
0.03 mole of
dissociate to give 0.03 mole of
ion and 0.03 mole of
ion
That means,
0.02 moles of
ion neutralize by 0.02 moles of
ion.
The excess moles of
ion = 0.03 - 0.02 = 0.01 mole
Total volume of solution = 100 + 300 = 400 ml = 0.4 L
Now we have to calculate the concentration of
ion.
![\text{Concentration of }H^+=\frac{\text{Moles of }H^+}{\text{Total volume}}](https://tex.z-dn.net/?f=%5Ctext%7BConcentration%20of%20%7DH%5E%2B%3D%5Cfrac%7B%5Ctext%7BMoles%20of%20%7DH%5E%2B%7D%7B%5Ctext%7BTotal%20volume%7D%7D)
![\text{Concentration of }H^+=\frac{0.01mole}{0.4L}=0.025M](https://tex.z-dn.net/?f=%5Ctext%7BConcentration%20of%20%7DH%5E%2B%3D%5Cfrac%7B0.01mole%7D%7B0.4L%7D%3D0.025M)
Now we have to calculate the pH of the solution.
![pH=-\log [H^+]](https://tex.z-dn.net/?f=pH%3D-%5Clog%20%5BH%5E%2B%5D)
![pH=-\log (0.025M)](https://tex.z-dn.net/?f=pH%3D-%5Clog%20%280.025M%29)
![pH=1.7](https://tex.z-dn.net/?f=pH%3D1.7)
Therefore, the pH of the solution is, 1.7
Answer: The equations of the above reactions are shown below
Explanation:
(a)
2K(s) + Cl2(g) ==> 2 KCl(s)
(b)
SrO(s) + H2O(aq) ==> Sr(OH)2(aq)
(c)
4Li(s) + O2(g) ==> 2Li2O(s)
(d)
2Na(s) + S (l) ===> Na2S