A compound of 2.225 g, known to be a carbohydrate, was analyzed and found to contain 0.890 g of carbon, 0.148 g of hydrogen and the rest was oxygen. How do you determine the percentage composition by mass of the compound?

Question

1905 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2017-05-19T14:20:26

#40.0% C#
#6.65% H#
#53.3% O#

The mass percentage of a substance in a compound is represented by the equation

#%compon ent = (g_(compon ent))/(g_(t otal)) xx 100%#

What we can do first is find it how much #O# is present, by subtracting the sum of the masses of #C# and #H# from the total mass:

#g_(O_2) = 2.225g - (0.890g + 0.148g) = 1.187g_(O_2)#

Now, let's use the above formula to calculate the percentage by mass of each component:

#%C = (0.890g)/(2.225g) xx 100% = 40.0%#

#%H = (0.148g)/(2.225g) xx 100% = 6.65%#

#%O = (1.187g)/(2.225g) xx 100% = 53.3%#