Answer:
C.) HOCl Ka=3.5x10^-8
Explanation:
In order to a construct a buffer of pH= 7.0 we need to find the pKa values of all the acids given below
we Know that
pKa= -log(Ka)
therefore
A) pKa of HClO2 = -log(1.2 x 10^-2)
=1.9208
B) similarly PKa of HF= -log(7.2 x 1 0^-4)= 2.7644
C) pKa of HOCl= -log(3.5 x 1 0^-8)= 7.45
D) pKa of HCN = -log(4 x 1 0^-10)= 9.3979
If we consider the Henderson- Hasselbalch equation for the calculation of the pH of the buffer solution
The weak acid for making the buffer must have a pKa value near to the desired pH of the weak acid.
So, near to value, pH=7.0. , the only option is HOCl whose pKa value is 7.45.
Hence, HOCl will be chosen for buffer construction.
Answer:
The light emitted by a light bulb is a form of radiation that occurs when the filament heats up and its thermal emission gains enough energy to move into the visible spectrum.
Explanation:
Light bulbs contain a filament which is heated up electrically. When this filament is heated up,energy in the form of heat is imparted to the electrons in the filament.
This thermal excitation of electrons ultimately leads to emission of light in the viable spectrum. This light is now radiated through a light bulb.
Answer:
the same
Explanation:
due to the law of conservation of mass, the mass will not change
Carbon-12 has the following electron configuration: 1s2-2s2-2p2. As seen in the configuration, the right answer is: the first electron shell has 4 orbitals.
Answer:
Hydrogen
Explanation:
Hydrogen is the only non metal in group on of the period table of elements.