Acetamide has the molecular formula CH3CONH2. Which element makes up the greatest percentage by mass of acetamide?

1 Answer
May 21, 2018

Carbon has the greatest percent by mass at 41%.

Explanation:

CH_3CONH_2

To find the mass, add all the elements' masses together. Let's make a list to find the mass by element.

Carbon (2 of them) - weighs 12.011g ; 2 of them, so multiply by 2:

12.011 * 2 = 24.022g

Hydrogen (5 of them) - weighs 1.008 ; 5 of them, so multiply by 5:

1.008 * 5 = 5.040g

Oxygen (1 of them) - weighs 15.999g
Nitrogen (1 of them) - weighs 14.007g

Add these numbers together:

24.022 + 5.040 + 15.999 + 14.007 = 59.068

Now, make a ratio of the highest amt. element to the whole:

24.022 / 59.068 = 0.40668382204

~0.41, or 41% Carbon