Confused
What is the percent composition of chlorine in PCl5?
Yes but you intended to type:
(177.5 / 208.5) x 100% = 85%
yes thank you Damon !!!
You are welcome.
Well, when it comes to PCl5, I guess you could say chlorine is "taking charge"! PCl5 stands for phosphorus pentachloride, which means there are 5 chlorine atoms. To find the percent composition of chlorine, we divide the molar mass of chlorine by the molar mass of PCl5 and multiply by 100. So, grab your calculator and let's figure out just how "elemental" this chlorine is!
To find the percent composition of chlorine (Cl) in phosphorus pentachloride (PCl5), we need to determine the mass of chlorine in one molecule of PCl5 and divide it by the molar mass of PCl5. Finally, multiplying by 100 will give us the answer in percentage.
Here are the steps to calculate the percent composition of chlorine in PCl5:
Step 1: Determine the molar mass of PCl5
The molar mass of PCl5 can be calculated by adding the atomic masses of phosphorus (P) and five chlorine atoms (Cl). Using a periodic table, we find:
Phosphorus (P) atomic mass = 30.97 g/mol
Chlorine (Cl) atomic mass = 35.45 g/mol
Molar mass of PCl5 = (1 * P) + (5 * Cl) = (1 * 30.97) + (5 * 35.45) = 30.97 + 177.25 = 208.22 g/mol
Step 2: Calculate the mass of chlorine in one molecule of PCl5
To find the mass of chlorine in one molecule of PCl5, we multiply the molar mass of chlorine by the number of chlorine atoms in PCl5. Since there are five chlorine atoms in PCl5, we use:
Mass of chlorine in PCl5 = (5 * Cl atomic mass) = (5 * 35.45) = 177.25 g/mol
Step 3: Calculate the percent composition of chlorine in PCl5
Finally, to determine the percent composition of chlorine in PCl5, we divide the mass of chlorine by the molar mass of PCl5 and multiply by 100:
Percent composition of chlorine = [(mass of Cl in PCl5) / (molar mass of PCl5)] * 100
= [(177.25 g/mol) / (208.22 g/mol)] * 100
= 85.1%
Therefore, the percent composition of chlorine in PCl5 is approximately 85.1%.
out of 6 atoms, five are Cl
However by mass it is
(100)(5*35.5) /(5*35.5 + 31)
31.0 + 5(35.5) = 208.5
35.5 x 5= 177.5
177.5% 208.5 x 100% = 85%