Question

According to Dalton, if 2 grams of element X combine with 4 grams of element Y to form compound XY, how many grams of element X would combine with 28 grams of element Y to form the same compound?

Answer 1

`14` grams

Explanation:

Well, the ratio between `XY` is `(2color(red)cancelcolor(black)"g")/(4color(red)cancelcolor(black)"g")=1/2`.

Since the ratio is constant, then if `Y=28 \ "g"`, then `X` is:

`X/(28 \ "g")=1/2`

`X=28 \ "g"*1/2`

`=14 \ "g"`

Answer 2

`"14 g"` of element X will be needed to combine with `"28 g"` of element Y.

Explanation:

The ratio of X to Y is 2X: 4Y. This can be reduced to 1X:2Y. So there will always be half as much element X as element Y in the compound XY. Half of `"28 g"` of element Y is `"14 g"` of element X.

So `"14 g"` of element X will be needed to combine with `"28 g"` of element Y.