If the percentage of arsenic is 76% and the percentage of oxygen is 24% how do I calculate the chemical composition of the oxide of the arsenic?
Thanks
Pretend you have 100 grams of the stuff.
Then 76 grams of As is how many moles?
76/74.9 =1.01 moles.
How many moles is 24 grams of O? 24/16=1.5
Now take the lowest mole number, and divide it into each to get a mole ratio.
As= 1.01/1.01=1
0= 1.5/1.01=1.5
so the ratio is 1/1.5 or in whole numbers, 2/3
As2O3
To calculate the chemical composition of the oxide of arsenic, you can follow these steps:
1. Assume you have 100 grams of the oxide of arsenic.
2. Determine the moles of arsenic (As) in 76 grams: Divide 76 grams by the molar mass of arsenic (74.9 g/mol) to get 1.01 moles of As.
3. Determine the moles of oxygen (O) in 24 grams: Divide 24 grams by the molar mass of oxygen (16 g/mol) to get 1.5 moles of O.
4. Find the smallest amount of moles (in this case, 1.01 moles of As).
5. Calculate the mole ratio by dividing each amount of moles by the smallest amount. In this case, divide 1.01 moles of As by 1.01 moles and 1.5 moles of O by 1.01 moles.
6. Simplify the ratio if possible to find the chemical composition. In this case, the simplified ratio is 2 moles of As to 3 moles of O.
7. Write the chemical formula by using the simplified ratio as subscripts. The chemical formula for the oxide of arsenic is As2O3.
So, the chemical composition of the oxide of arsenic is As2O3.