Hydrogen was passed over heated 2g copper oxide till only copper was left. The mass of copper obtained was was 1.6 grams. What is the percentage of oxygen in copper oxide?

The stoichiometrically balanced equation tells us unequivocally that $1$ $mol$ dihydrogen reacts with $0.50$ $mol$ dioxygen to give $1$ $mol$ water. $"Moles of dihydrogen"$ $=$ $(58.1*g)/(2.02*g*mol)$ $=$ $28.7*mol$ $H_2$ $"Moles...

We need a stoichiometric equation for water synthesis: $H_2(g) + 1/2O_2(g) rarr H_2O(l)$ Clearly, dihydrogen must be present in a 2:1 molar ratio with respect to dioxygen. $"Moles of dihydrogen"$...

Trying to present a possible Answer We know that the molar mass of carbon and hydrogen are $C=12"g/mol" and H = 1"g/mol"$ When Carbon Hydrogen mass ratio is 11.89 The...

The empirical formulas are $"Cu"_2"O"$ and $"CuO"$. Oxide 1 $color(white)(mmmmml)"Cu" +color(white)(m) "O" → "Oxide 1"$ $"Mass/g":color(white)(l) 2.118color(white)(ll) 0.2666$ Our job is to calculate the ratio of the moles of...

Recall that by using the molar mass of an element and the mass of the element in the sample, you can find the amount of moles in the sample. We're...

You haven't given us the constituent percentage of hydrogen. Would you review the question? Once we have $%H$ we can address the question.

First write down a balanced chemical equation for the reaction : $H_2+I_2->2HI$ This represents ratio in which chemicals combine. Now calculate the number of moles of each reactant present :...

$CaCO_3(s) + Delta rarr CaO(s) + CO_2(g)uarr$ The $Delta$ symbol represents heat, and you have to fiercely heat these carbonates to effect decomposition. Note that this reaction is certainly stoichiometrically...

The trick here is to recognize the fact that argon will not react with the hot copper and the hot magnesium, but the oxygen and the nitrogen gas present in...

$30 - 20 = 10$