Question

I need help I don’t really get it

Answer 1

The answer is 17.75%.

Step-by-step explanation:

We are given
`NH_(3)` (ammonia) as a chemical formula. We want to find the percent composition of the formula.

We are given the atomic masses of each element:
`H = 1.008 amu` and
`N = 14.01 amu`. Then, we need to find out how many atoms are present of each element in the compound.

N has one atom (no subscript present). H has three atoms (subscript of 3 is present).

Now, we simply multiply the masses of each element by the number of atoms present of that element.

`H = 1.008amu * 3atoms = 3.024amu`

`N = 14.01amu * 1 atom = 14.01 amu`

Then, we add up those products to get the mass of the formula.

`3.024amu + 14.01amu = 17.034amu`

Finally, we divide the masses of each element by the mass of the formula to get the percentages of each element present in the compounds.

For hydrogen:

`(3.024amu)/(17.034 amu) =0.1775`

`0.1775 * 100 = 17.75`

Hydrogen atoms account for 17.75% of the compound.

For nitrogen:

`(14.01amu)/(17.034amu) = 0.8225`

`0.8225 * 100 = 82.25`

Nitrogen atoms account for 82.25% of the compound.

For an extra step, add up the percentages to make sure you get within 100 ± 0.01. Otherwise, you may have rounded incorrectly or miscalculated somewhere within your work.

Hope this helps!