Final answer:
The percent composition of a compound is calculated by determining the molecular weight of the compound and comparing it to the mass contribution of each element, then converting that value into a percentage. Similar methods are used to calculate the percent composition of hydrazoic acid, TNT, and the sulfate ion in Al2(SO4)3 as well as the percent ammonia in Co(NH3)6Cl3 and the percent water in CuSO4.5H2O.
Step-by-step explanation:
Percent Composition Calculation
To calculate the percent composition of any compound, you need to know the formula of the compound and the atomic weights of the elements contained in it. For the calculation, follow these steps:
Determine the molecular weight of the compound by adding up the atomic weights of all atoms in its formula.
Find the total mass contribution of each element by multiplying the atomic weight of the element by the number of atoms of that element in the formula.
Divide the mass contribution of each element by the molecular weight and multiply by 100 to get the percent composition.
For NH3 (ammonia), you would use the atomic weights of nitrogen (14.01 g/mol) and hydrogen (1.008 g/mol) to calculate the molecular weight and then find the percent composition of each element.
The same steps apply for calculating the percent composition of HN3 (hydrazoic acid), TNT (C6H2(CH3)(NO2)3), and the percent of SO4²- in Al2(SO4)3.
To determine the percent ammonia in Co(NH3)6Cl3, multiply the mass contribution of NH3 by six (since there are six NH3 units), divide by the formula weight of Co(NH3)6Cl3, and multiply by 100. For the percent water in CuSO4.5H2O, multiply the mass of the five water molecules by their respective molecular weight and proceed similarly.