What information is need to calculate the percent composition of a compound?
1 answer:
Answer:
Molecular formula
Explanation:
Molecular formula in the first place is required to understand which compound we have. We then should refer to the periodic table and find the molecular weight for each atom. Adding individual molecular weights together would yield the molar mass of a compound.
Then, dividing the total molar mass of a specific atom by the molar mass of a compound and converting into percentage will provide us with the percentage of that specific atom.
E. g., calculate the percent composition of water:
- molecular formula is
;
- calculate its molar mass: [tex]M = 2M_H + M_O = 2\cdot 1.00784 g/mol + 16.00 g/mol = 18.016 g/mol;
- find the percentage of hydrogen: [tex]\omega_H = \frac{2\cdot 1.00784 g/mol}{18.016 g/mol}\cdot 100 \% = 11.19 %;
- find the percentage of oxygen: [tex]\omega_O = \frac{16.00 g/mol}{18.016 g/mol}\cdot 100 \% = 88.81 %.
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Answer:
The concentration of NaCl = 0.3374 M
Explanation:
Given :
Molarity of AgNO₃ = 0.2503 M
Volume of AgNO₃ = 20.22 mL
The conversion of mL into L is shown below:
Thus, volume of the solution = 20.22×10⁻³ L
Molarity of a solution is the number of moles of solute present in 1 L of the solution.
The formula can be written for the calculation of moles as:
Thus,
The chemical reaction taking place:
According to reaction stoichiometry:
<u>1 mole</u> of AgNO₃ reacts with <u>1 mole</u> of NaCl
Thus,
5.0611×10⁻³ moles of AgNO₃ reacts with 5.0611×10⁻³ moles of NaCl
Thus, moles of NaCl required = 5.0611×10⁻³ moles
Volume of NaCl required = 15.00 mL
The conversion of mL into L is shown below:
Thus, volume of the solution = 15.00×10⁻³ L
Applying in the formula of molarity as:
<u>Thus, the concentration of NaCl = 0.3374 M</u>