A. A pure chemical substance consisting of one type of atom
First we have to find Ka1 and Ka2
pKa1 = - log Ka1 so Ka1 = 0.059
pKa2 = - log Ka2 so Ka2 = 6.46 x 10⁻⁵
Looking at the values of equilibrium constants we can see that the first one is really big compared to second one. so, the pH will be affected mainly by the first ionization of the acid.
Oxalic acid is H₂C₂O₄
H₂C₂O₄ ⇄ H⁺ + HC₂O₄⁻
0.0356 M 0 0
0.0356 - x x x
Ka1 =
![\frac{[H^+][HC2O4^-]}{[H2C2O4]}](https://tex.z-dn.net/?f=%20%5Cfrac%7B%5BH%5E%2B%5D%5BHC2O4%5E-%5D%7D%7B%5BH2C2O4%5D%7D%20)
= x² / 0.0356 - x
x = 0.025 M
pH = - log [H⁺] = - log (0.025) = 1.6
The empirical formula : MnO₂.
<h3>Further explanation</h3>
Given
632mg of manganese(Mn) = 0.632 g
368mg of oxygen(O) = 0.368 g
M Mn = 55
M O = 16
Required
The empirical formula
Solution
You didn't include the pictures, but the steps for finding the empirical formula are generally the same
- Find mol(mass : atomic mass)
Mn : 0.632 : 55 = 0.0115
O : 0.368 : 16 =0.023
- Divide by the smallest mol(Mn=0.0115)
Mn : O =

The empirical formula : MnO₂
I don’t! Know bit I guess it’s C
The maximum safe operating temperature for this reaction is equal to 895°C.
<u>Given the following data:</u>
- Width of cylinder = 22 cm.
- Maximum safe pressure = 6.30mpa.
<u>Scientific data:</u>
- Ideal gas constant, R = 8.314 L-kPa/Kmol.
- Molar mass of of dinitrogen monoxide (
) gas = 66 g/mol.
Radius, r = 
<h3>How to calculate the maximum safe operating temperature.</h3>
First of all, we would determine the volume of the stainless-steel cylinder by using this formula:

Volume, V = 10,036.81
.
In liters, we have:
Volume, V = 10.04 Liters.
Next, we would determine the number of moles of dinitrogen monoxide (
) gas:

Number of moles = 8.136 moles.
Now, we can solve for the maximum safe operating temperature by applying the ideal gas equation:

T = 895.02 ≈ 895°C.
Read more on temperature here: brainly.com/question/24769208