Molarity of acid=2.5M
pH=5.1.
ka=?
Now
We need to write an eqn to show the dissociation of the acid
HA + H2O === H3O+ + A-
Writing The Equilibrium(Or Acid dissociation constant) of this reaction
Ka =[H3O+] {A-]/ {HA].
The concept behind this is
concentration of Products divided by those of reactants. Water is not written because its a pure liquid and does not affect the Equilibrium constant.
Now If you have any Idea on ICE tables..
You'd know that the concentration of acid will decrease by 2.5-x
Whilst the products...will increase by x each
Note: This is when the ratio of their Moles are in 1:1
ka= x.x/2.5-x
Since the Moles of A- and H3O+ are in 1:1... Their concentrations at equilibrium will be the same
so
Ka= x²/2.5-x
Now what is x??
x is the Hydrozonium ion concentration.
we can get it from the pH formula
pH= -log (H3O+)
Making H3O+ subject by applying Logarithm Rules
H3O+ = 10^-ph
x=10^-5.1
=7.94x10^-6.
Now back to Ka
Ka= x²/2.5-x
Ka= (7.94x10^-6)²/2.5-(7.94x10^-6)
Ka= (7.94x10^-6)²/2.4999
Ka= 2.52x10^-11.
Was a Fun One
Answer:
A
Explanation:
I took a test like this and my teacher said this was right so ye. hopefully I remembered correctly if its wrong im sorry ;C
Both the pure hydrogen and hydrogen bromide is held by weak intermolecular forces of attaction between molecules. Bromide has larger size of electron cloud than Hydrogen, leading to a greater extent of polarisation of the electron cloud. This results in stronger van der Waals' forces of attraction in hydrogen bromide compared to the pure hydrogen. More energy is required to break the stronger bonds in hydrogen bromide than pure hydrogen, leading to a higher boiling point in hydrogen bromide. Thus, pure hydrogen has a lower boiling point.
Explanation:
the strength of intermolecular forces of attraction rely on the size of the electron cloud. the greater the atomic number, the greater the size of the electron cloud and thus, the stronger the forces of attraction.
When asnwering a qn, you want to first state the structure and bonding of the compound, then compare the size of their electron clouds.
Answer structure:
greater size of electron clouds -> greater extent of polarisation of electron cloud -> stronger van der Waals' forces of attraction -> more energy required to overcome the bonds -> higher boiling point
Answer:
Explanation:
Hello!
In this case, since the writing of a net ionic equation first implies writing the complete molecular equation:
We can see that HCl and MgCl2 are ionized because they are aqueous, thus we write:
In such a way, we can cancel out the chloride ions as they are the spectator ones to obtain the net ionic one:
Best regards!