Ammonia reacts with phosphoric acid to form a compound that contains 28.2%
nitrogen, 20.8% phosphorous, 8.1% hydrogen and 42.9% oxygen. Calculate the
empirical formula of this compound.answer my question no spams
Answers
Solution:
1) Masses:
N ⇒ 28.2 g
P ⇒ 20.8 g
O ⇒ 42.9 g
H ⇒ 8.1 g
2) Moles:
N ⇒ 2
P ⇒ 0.67
O ⇒ 2.68
H ⇒ 8
3) Lowest whole-number ratio:
N = 2 / 0.67 = 3
P = 0.67 / 0.67 = 1
O = 2.68 / 0.67 = 4
H = 8 / 0.67 = 12
4) Empirical formula:
N3H12PO4
or
(NH4)3PO4
Although not asked for, the name of this compound is ammonium phosphate.
5) I would like to discuss my piece of advice (about thirds) at the top of the file using the moles data from the above problem.
N ⇒ 2 = 6/3
P ⇒ 0.67 = 2/3
O ⇒ 2.68 = 8/3
H ⇒ 8 = 24/3
6) Then, I multiply:
N ⇒ 6/3 times 3 = 6
P ⇒ 2/3 times 3 = 2
O ⇒ 8/3 times 3 = 8
H ⇒ 24/3 times 3 = 24
7) Notice how doing it this way introduces an extra factor of 2. We remove the extra factor of two to arrive at this ratio:
N ⇒ 3
P ⇒ 1
O ⇒ 4
H ⇒ 12
8) And we continue on. I really don't want you to think that the introduction of the extra factor of two damages this technique. There are times when changing everything to third-type fractions will make things easier.
Answer:
the reaction between phosphoric acid and ammonia, a compound forms containing 28.2 grams nitrogen, 8.1 grams hydrogen, 20.8 grams phosphorus, and 42.9 grams oxygen by mass. a. ... 20.8 g P x 1 mol P = 0.672 mol P 30.97 g P 42.9 g O x 1 mol O = 2.69 mol O 16.00 g O Step 2: 2.01 mol N = 2.991 mol of N = 3 mol .