Simple Math Problem Please help?

Question

Chemistry students analyzed the contents of rust. They found that it is made up of iron and oxygen. Tests on samples of rust gave this data.


Amt Of Rust (G)
50
100
135
150

Amt. Of Iron (G)
35.0
70.0
94.5
105.0

Amt. Of Oxygen (G)
15.0
30.0
40.5
45.0



A. Suppose the students analyze 400 grams of rust. How much iron and how much oxygen should they find?
Show Your work.

Answer 1

Divide quantity of oxygen by quantity of rust;

15 / 50 = .3 ;

Multiply the percentage (in decimal form; .3 = 30%) by the total amount of rust;

.3 * 400 = 120

Answer = 120 (G) Oxygen


Divide quantity of iron by quantity of rust;

35 / 50 = .7;

Multiply the percentage (in decimal form; .7 = 70%) by the total amount of rust;

.7 * 400 = 280

Answer = 280 (G) Iron

So we have;

120 (G) of oxygen

280 (G) of iron

Hope this helps!

: )

Answer 2

50 Rust, 35 Iron, 15 Oxygen,
35/50=0.7 =70% Iron, 15/50=0.3=30% Oxygen

So if there is 400 grams of rust then
400x0.70=280 grams of Iron
400x0.30=120 grams of oxygen

If the measurements were all a little different then you would add up all the rust and use the sum of all the iron and the sum of all the oxygen which would make this:

50+100+135+150=435 rust
304.5 Iron
130.5 Oxygen
304.5/435=0.7
130.5/435=0.3

This would take the average of your measurements. But all are the same ratio.

Answer 3

If you take the grams of rust that were tested you will see that consistently the amount of Iron is 0.7 grams. 35.0 divided by 50 equals 0.7. This equation works for all of the rust to iron ratios. At 400 grams of rust you will find 280 grams of iron. 280 divided by 400 equals 0.7. The amount of rust tested equals to 0.3% of the oxygen is every case. You must find out what amount, in grams, of oxygen equals to 0.3% when divided by 400 grams of rust. I will let you figure that part out.

Answer 4

280 iron and 120 oxygen; four times the third set of data