Answer:
Explanation:
the chemical equilibrium constant can be easily calculated since the concentrations at equilibrium are given.the calculation shows the value of Kc for the reversible reaction and forward reaction
The nuclei of atoms also contain neutrons, which help hold the nucleus together. ... The total weight of an atom is called the atomic weight. It is approximately equal to the number of protons and neutrons, with a little extra added by the electrons.
The mass of a given atom, measured on a scale in which the hydrogen atom has the weight of one. Because most of the mass in an atom is in the nucleus, and each proton and neutron has an atomic weight near one, the atomic weight is very nearly equal to the number of protons and neutrons in the nucleus.
Answer:
Average atomic mass = 10.812 amu
Explanation:
The formula for the calculation of the average atomic mass is:
Given that:
<u>For first isotope, Boron-10:
</u>
% = 19.8 %
Mass = 10.013 amu
<u>For second isotope, Boron-11:
</u>
% = 80.2 %
Mass = 11.009 amu
Thus,
<u>Average atomic mass = 10.812 amu</u>
Answer:
pKa = 3.675
Explanation:
∴ <em>C</em> X-281 = 0.079 M
∴ pH = 2.40
let X-281 a weak acid ( HA ):
∴ HA ↔ H+ + A-
⇒ Ka = [H+] * [A-] / [HA]
mass balance:
⇒<em> C</em> HA = 0.079 M = [HA] + [A-]
⇒ [HA] = 0.079 - [A-]
charge balance:
⇒ [H+] = [A-] + [OH-]... [OH-] is negligible; it comes from to water
⇒ [H+] = [A-]
∴ pH = - log [H+] = 2.40
⇒ [H+] = 3.981 E-3 M
replacing in Ka:
⇒ Ka = [H+]² / ( 0.079 - [H+] )
⇒ Ka = ( 3.981 E-3 )² / ( 0.079 - 3.981 E-3 )
⇒ Ka = 2.113 E-4
⇒ pKa = - Log ( 2.113 E-4 )
⇒ pKa = 3.675
Answer : The given statement is, false.
Explanation :
Ionic product of water : It is defined as the product of the concentration of hydrogen ion and the concentration of hydroxide ion.
The mathematical expression will be,
![[H^+][OH^-]=10^{-14}](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%5BOH%5E-%5D%3D10%5E%7B-14%7D)
When the concentration of hydrogen ion and hydroxide ion are equal then the solution is neutral and the value will be, 
. And the pH of the solution is, 7.
When the concentration of hydrogen ion is greater than then the solution is acidic in nature. And the pH of the solution is, less than 7.
When the concentration of hydrogen ion is less than then the solution is basic in nature. And the pH of the solution is, greater than 7.
Hence, the given statement is false.
