Question

4 gms of hydrogen are ignited with 4 gms of oxygen. the weight of water formed ?

Answer 1

`"Mass"~=4.5*g`

Explanation:

We need (i), a stoichiometric equation,

`H_2(g) + 1/2O_2(g) rarr H_2O(l)`.

We have `(4*g)/(32.0*g*mol^-1)=1/8*mol` `"dioxygen gas"`.

And `(4*g)/(2.0*g*mol^-1)=2*mol` `"dihydrogen gas"`.

Clearly, the `"dioxygen gas"` is present in DEFICIENCY, and `O_2` is the limiting reagent.

Given the equation, we can make at most `1/4*mol` of water, i.e. a mass of `1/4*cancel(mol)xx18.01*g*cancel(mol^-1)=??*g`