First, we will get the average pH of the two given values:
average pH = (6.4+8) / (2) = 7.2
At this average pH, the concentration of the acid from the phenol red is equal to the concentration of the base.
pH = 7.2
[H+] = 10^(-7.2) = 6.3 * 10^-8
Phenol red has the general formula HA, this gives us:
HA <.......> H+ + A-
At pH = 7.2, [H+] = [A-]
<span>Ka = [H+][A-]/ [HA]
</span>Ka = [H+] = <span>6.3 x 10^-8</span>
Answer:

Explanation:
If l = 3, the electrons are in an f subshell.
The number of orbitals with a quantum number l is 2l + 1, so there
are 2×3 + 1 = 7 f orbitals.
Each orbital can hold two electrons, so the f subshell can hold 14 electrons.

I think it will be letter A tbh
Hope this helps you out
Answer:
2RbNO2 + BaCO3 → Rb2CO3 + Ba(NO2)2
Explanation:
The balanced reaction equation is shown below;
2RbNO2 + BaCO3 → Rb2CO3 + Ba(NO2)2
This reaction is possible because the reduction potential of Rb is -2.98V while that of Ba is –2.92 V. Hence Rb can displace Ba from its salt solution.
The equation is balanced since the number of atoms of each element on the left and right hand sides of the reaction equation are equal.
Answer:
3040 mmHg
Explanation:
Here
we have to convert 4.00 atm to mmHg
As we know that
The number of atm in 1 mmHg is 0.0013157895567935
Now there is 4.00 atm So, in mmHg it would be
And, according to this, the working is given below:
= 4 ÷ 0.0013157895567935
= 3,039.99
= 3040 mmHg
Hence, the last option is correct
And, the same is relevant and considered too