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:
Fe
Explanation:
The electrical conductivity depends mainly on the type of chemical bonds between the atoms of a compound.
In the case of MgF2, FeCl3 and FeO3, these have the type of ionic bond. This means that in the atoms of the compound there is an electron transfer, to keep eight electrons in the outermost layer and thus resemble the electronic configuration of the inert gas closest to each of the two elements, due to this ions of opposite charges are formed that are held together by electrostatic forces. These types of compounds are good conductors of electricity, however, to have this property, they must be dissolved in water or molten.
In the case of Fe, however, the type of union between atoms is metallic. In this type of junction, valence electrons are quite free inside the metal, which makes it easy for them to move. For this reason, this compound will conduct electricity in a solid state.
Answer:
Independent
Explanation:
Independent Variable is the volume of the object. Dependent Variable is the mass of the object. So it
The SI unit for the amount of substance present is the mole.
The mole is defined as the amount of substance that has the same amount of particles as there are atoms in 12 grams of carbon-12. Mathematically, the moles of a substance may be computed using:
moles present = mass of substance / molecular mass of substance
