Answer:
1.0 M
Explanation:
Reaction equation;
KOH(aq) + HCl(aq) -----> KCl(aq) + H2O(l)
Concentration of acid CA = ?
Concentration of base CB = 1.0 M
Volume of base VB = 25.60 - 0.50 = 25.1 ml
Volume of acid VB = 25.0 ml
Number of moles of acid NA = 1
Number of moles of base NB =2
CAVA/CBVB =NA/NB
CAVANB = CBVBNA
CA = CBVBNA/VANB
CA = 1 * 25.1 * 1/25.0 *1
CA = 1.0 M
Explanation:
the pH of the solution defined as negatuve logarithm of
ion concentration.
![pH=-\log[H^+]](https://tex.z-dn.net/?f=pH%3D-%5Clog%5BH%5E%2B%5D)
1. Hydrogen ion concentration when pH of the solution is 11.
![11=-\log[H^+]](https://tex.z-dn.net/?f=11%3D-%5Clog%5BH%5E%2B%5D)
..(1)
At pH = 11, the concentration of
ions is
.
2. Hydrogen ion concentration when the pH of the solution is 6.
![6=-\log[H^+]'](https://tex.z-dn.net/?f=6%3D-%5Clog%5BH%5E%2B%5D%27)
..(2)
At pH = 6, the concentration of
ions is
.
3. On dividing (1) by (2).
![\frac{[H^+]}{[H^+]'}=\frac{1\times 10^{-11} mol/L}{1\times 10^{-6} mol/L}=1\times 10^{-5}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BH%5E%2B%5D%7D%7B%5BH%5E%2B%5D%27%7D%3D%5Cfrac%7B1%5Ctimes%2010%5E%7B-11%7D%20mol%2FL%7D%7B1%5Ctimes%2010%5E%7B-6%7D%20mol%2FL%7D%3D1%5Ctimes%2010%5E%7B-5%7D%20)
The ratio of hydrogen ions in solution of pH equal to 11 to the solution of pH equal to 6 is
.
4. Difference between the
ions at both pH:

This means that Hydrogen ions in a solution at pH = 7 has
ions fewer than in a solution at a pH = 6
Oxidation state of Pb in PbO2 is +4.
Oxidation state of Pb in PbCl2 is +2.
Oxidation state of Pb in Pb2O is +1.
Oxidation state of Pb in Pb4O3 is +6/4.
Hence option A. PbO2 is correct.
Hope this helps, have a nice day!
Answer:
frequency of light (f) = 1 x 10¹⁵s⁻¹
Explanation:
Given Data:
Wavelength of light λ = 3.0 x10⁻⁷m
Frequency of light: to be calculated
Formula Used to find frequency:
f = V/λ ........................... (1)
where
f is the frequency
V is the velocity
λ is wavelength
Velocity of light = 3 x 10⁸ ms⁻¹
put the values in equation (1)
f = 3 x 10⁸ ms⁻¹ / 3.0 x10⁻⁷m
f = 1 x 10¹⁵s⁻¹
So the frequency of light = 1 x 10¹⁵s⁻¹
Answer : The value of equilibrium constant for this reaction at 262.0 K is 
Explanation :
As we know that,

where,
= standard Gibbs free energy = ?
= standard enthalpy = -45.6 kJ = -45600 J
= standard entropy = -125.7 J/K
T = temperature of reaction = 262.0 K
Now put all the given values in the above formula, we get:


The relation between the equilibrium constant and standard Gibbs free energy is:

where,
= standard Gibbs free energy = -12666.6 J
R = gas constant = 8.314 J/K.mol
T = temperature = 262.0 K
K = equilibrium constant = ?
Now put all the given values in the above formula, we get:


Therefore, the value of equilibrium constant for this reaction at 262.0 K is 