A compound of nitrogen and oxygen is 36.8% nitrogen. A second compound of nitrogen and oxygen is 25.9% nitrogen. What is the ratio of masses of oxygen in the two compounds per gram of nitrogen?

Assume you have one hundred grams of each compound to make dealing with the percentages easier.

Compound 1)

N: 36.8g
O: 100g - 36.8g = 63.2g oxygen/36.8g nitrogen = 1.7g oxygen/1g nitrogen

Essentially, if you round the numbers up, it's a 2:1 ratio of oxygen to nitrogen.

Compound 2)

N: 25.9g
O: 100g - 25.9g = 74.1g oxygen/25.9g nitrogen = 2.86g oxygen/1g nitrogen

Here, if you round up, it would be a 3:1 ratio of oxygen to nitrogen.

Disclaimer: Someone correct me if I'm wrong, as I'm completely out of the loop today.

That was the answer I had, but apparently the correct answer is 5:3??? I have no idea how they're getting that.

Let's go back to the 1.717 for the first one and 2.86 for the second. I think you have interpreted the problem wrong. You have calculated the ratio of N to O in each but I think the problem wants to calculate the ratio of the O in the first one to the O in the second one.We can do that by using the 1.717 for O in the first one per 1g N and 2.86 for O in the second one per 1g N.

Now the ratio of the two is
1.717/1.717 = 1.000
2.86/1.717 = 1.666
To try to find the small whole numbers, the easy way is to multiply by 2 to obtain 2.00 to 3.33 which doesn't work so we try multiplying by 3 and we get
3.00 to 5.00. I think that is the answer you are looking for.

That makes sense!! Thank you!

To find the ratio of masses of oxygen in the two compounds per gram of nitrogen, we need to compare the mass of oxygen to the mass of nitrogen in each compound.

Let's assume the first compound has a total mass of 100 grams. Since it is 36.8% nitrogen, we can calculate the mass of nitrogen in the compound as 36.8 grams (100 grams multiplied by 36.8%). Since the compound is made up of only nitrogen and oxygen, the remaining mass must be oxygen. Therefore, the mass of oxygen in the first compound is 100 grams - 36.8 grams = 63.2 grams.

Now, let's consider the second compound. Using a similar calculation, we can find that the mass of nitrogen in the second compound, assuming a total mass of 100 grams, is 25.9 grams. Hence, the mass of oxygen in the second compound is 100 grams - 25.9 grams = 74.1 grams.

Finally, we can compare the ratios of oxygen mass to nitrogen mass in the two compounds by dividing the mass of oxygen in each compound by the mass of nitrogen.

For the first compound: 63.2 grams of oxygen / 36.8 grams of nitrogen = 1.715
For the second compound: 74.1 grams of oxygen / 25.9 grams of nitrogen ≈ 2.861

Therefore, the ratio of masses of oxygen in the two compounds per gram of nitrogen is approximately 1.715:2.861, or simplifying it further, approximately 1:1.7.