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
The formation of hydrogen cyanide, HCN is formed by reacting hydrogen gas, carbon and nitrogen gas, expressed in the following expression below:
<span>½ H2 (g) + C (s) + ½ N2 (g) → HCN (g) ΔHof = 135 kJ
</span>
At standard conditions, hydrogen and nitrogen exist as gases while carbon is solid. This is also an endothermic reaction due to the positive <span>ΔHof</span>
Answer: The formula for this hydrate is 
Explanation:
Decomposition of hydrated copper sulphate is given by:
Molar mass of 
= 160 g/mol
According to stoichiometry:
(160+18x) g of 
decomposes to give 160 g of anhydrous
Thus 42.75 g of decomposes to give=
g of anhydrous
Thus the formula for this hydrate is
K ---> 38.7 g / 39.1 g/mol = 0.99
N ---> 13.9 g / 14.0 g/mol = 0.99
O ---> 47.4 g / 16.0 g/mol = 2.96
Divide by smallest:
K ---> 0.99 / 0.99 = 1
N ---> 0.99 / 0.99 = 1
O ---> 2.96 / 0.99 = 3
KNO3
<span>magnesium oxide is a compound that is composed of one atom of magnesium and two atoms of oxygen. The compound is a combination of Mg2+ ion and O2-. The ions translate into atoms which reflects on the subscripst of the elements already. magnesium oxide is a basic oxide with the pH level greater than 7.</span>
