I will show you with detailed work for NaCl, but follow the same procedure for the rest of the compounds.
Molar Mass - Find the molar mass of the Na and the Cl and add them together
Na - 23
Cl - 35.5
Add those numbers together 23 + 35.5 = 58.5 g/mol
Moles in 1 tsp:
The mass measured in 1tsp of NaCl was 18 g. To calculate the amount of moles you take the mass measured and divide it by the molecular weight.
18/58.5 = 0.3077 mol
Moles of each element:
To find the moles each element in the compound you multiply the moles of 1 tsp by the number of atoms of the element in the compound
Na - 1 in NaCl
Cl - 1 in Na Cl
so take 0.3077 * 1 = 0.3077 moles Na (and Cl in this case)
Atoms of each:
take the number of moles calculated and multiply that by Avogadro's number(6.023x10^23) for the number of molecules
So for both Na and Cl:
0.3077 * 6.023x10^23 = 1.853x10^23 atoms for both Na and Cl
<span>Zn⁰(s) + CuSO4(aq) --> Zn²⁺SO4²⁻(aq) + Cu(s)
</span>Zn⁰ --- in free elements oxidation number is 0.
Zn²⁺SO4²⁻ ---- ionic compound , it has ion Zn²⁺, so oxidation number here is +2.
<span>The oxidation number of Zn changes from 0 to +2.</span>
pH=2.7
<h3>Further explanation</h3>
Acetic acid = weak acid
![\tt [H^+]=\sqrt{Ka.M}](https://tex.z-dn.net/?f=%5Ctt%20%5BH%5E%2B%5D%3D%5Csqrt%7BKa.M%7D)
Ka = acid ionization constant
M = molarity
Ka for Acetic acid(CH₃COOH) : 1.8 x 10⁻⁵
![\tt [H^+]=\sqrt{1.8\times 10^{-5}\times 0.222}\\\\=0.001998=1.998\times 10^{-3}](https://tex.z-dn.net/?f=%5Ctt%20%5BH%5E%2B%5D%3D%5Csqrt%7B1.8%5Ctimes%2010%5E%7B-5%7D%5Ctimes%200.222%7D%5C%5C%5C%5C%3D0.001998%3D1.998%5Ctimes%2010%5E%7B-3%7D)
Answer: a) 
is the limiting reagent
b) 3.59 g
c) 11.6g
Explanation:
To calculate the moles :
According to stoichiometry :
a) 9 moles of require= 4 moles of 
Thus 0.15 moles of will require=
of 
Thus is the limiting reagent as it limits the formation of product and is the excess reagent.
b) As 9 moles of give = 8 moles of
Thus 0.15 moles of give =
of
Mass of 
c) As 9 moles of give = 3 moles of 
Thus 0.15 moles of give =
of
Mass of 
Unicellular had one cell and multicellular has more than one
