Answer:
To calculate the number of atoms in a sample, divide its weight in grams by the amu atomic mass from the periodic table, then multiply the result by Avogadro's number: 6.02 x 10^23. Set up Equation Express the relationship of the three pieces of information you need to calculate the number of atoms in the sample in the form of an equation.
There is an error in the first sentence of the question; the right format is:
Suppose a 500.mL flask is filled with 1.9mol of NO3 and 1.6mol of NO2.
It should be NO2 and not NO.
Answer:
The equilibrium molarity of NO = 0.21695 m
Explanation:
Given that :
the volume = 500 mL = 0.500 m
number of moles of 
number of moles of 
Then we can calculate for their respectively concentrations as :
![[NO_3] = \frac{number \ of \ moles}{volume}](https://tex.z-dn.net/?f=%5BNO_3%5D%20%3D%20%5Cfrac%7Bnumber%20%5C%20of%20%5C%20moles%7D%7Bvolume%7D)
![[NO_3] = \frac{1.9}{0.500}](https://tex.z-dn.net/?f=%5BNO_3%5D%20%3D%20%5Cfrac%7B1.9%7D%7B0.500%7D)
![[NO_3] = 3.8 \ M](https://tex.z-dn.net/?f=%5BNO_3%5D%20%3D%203.8%20%5C%20M)
![[NO_2] = \frac{number \ of \ moles}{volume}](https://tex.z-dn.net/?f=%5BNO_2%5D%20%3D%20%5Cfrac%7Bnumber%20%5C%20of%20%5C%20moles%7D%7Bvolume%7D)
![[NO_2] = \frac{}{} \frac{1.6}{0.500}](https://tex.z-dn.net/?f=%5BNO_2%5D%20%3D%20%5Cfrac%7B%7D%7B%7D%20%5Cfrac%7B1.6%7D%7B0.500%7D)
![[NO_2] = 3.2 \ M](https://tex.z-dn.net/?f=%5BNO_2%5D%20%3D%203.2%20%5C%20M)
The chemical reaction can be written as:

The ICE table is as follows;

Initial 3.8 - 3.2
Change +x x -2x
Equilibrium 3.8+x +x 3.2 - 2x
![K_c=\frac{[NO_2]^2}{[NO_3][NO]}](https://tex.z-dn.net/?f=K_c%3D%5Cfrac%7B%5BNO_2%5D%5E2%7D%7B%5BNO_3%5D%5BNO%5D%7D)



Using quadratic formula;

= 
= 0.21695 OR -3.7283
Going by the positive value;
x = 0.21695
![[NO_3] = 3.8 +x = 3.8 + 0.21695](https://tex.z-dn.net/?f=%5BNO_3%5D%20%3D%203.8%20%2Bx%20%20%3D%203.8%20%2B%200.21695)
= 4.01695 m
[NO] = x = 0.21695 m
![[NO_2] = 3.2 +x = 3.2 + 0.21695](https://tex.z-dn.net/?f=%5BNO_2%5D%20%3D%203.2%20%2Bx%20%20%3D%203.2%20%2B%200.21695)
= 3.41695 m
Answer:
strength and vitality required for sustained physical or mental activity
Explanation: