A 230 g sample of a compound contains 136.6 g of carbon, 26.4 g of hydrogen, and 31.8 g of nitrogen. The rest is oxygen. What is the mass percent of oxygen in the compound?
230-(136.6+26.4+31.8) = 35.2
So, oxygen = 35.2/230 = .153 = 15.3%
What is the empirical formula of a phosphoric acid that contains 0.3086 g of hydrogen, 3.161 g of phosphorus, and 6.531 g of oxygen?
To find the mass percent of oxygen in the compound, we need to determine the amount of oxygen present in the 230 g sample.
First, we find the sum of the masses of carbon, hydrogen, and nitrogen:
136.6 g (carbon) + 26.4 g (hydrogen) + 31.8 g (nitrogen) = 194.8 g
Next, we subtract this sum from the total mass of the compound to find the mass of oxygen:
230 g (total mass) - 194.8 g (sum of carbon, hydrogen, and nitrogen) = 35.2 g
Now we can calculate the mass percent of oxygen:
(Mass of oxygen / Total mass of compound) x 100
(35.2 g / 230 g) x 100 = 15.3 %
Therefore, the mass percent of oxygen in the compound is 15.3%.