Tag: evs

$1.375$ g of cupric oxide was reduced by heating in a current of hydrogen and the weight of copper obtained was $1.098$ g. In another experiment, $1.156$ g of copper was dissolved in nitric acid and the resulting solution was evaporated to dryness. The residue of copper nitrate when strongly heated was converted into $1.4476$ g of cupric oxide. State the law illustrated by these chemical combinations.

A pair of compounds which is an illustration of law of multiple proportions is:

Any sample of pure water, irrespective of its source, contains 88.89% oxygen and 11.11 % hydrogen by mass. The data supports the:

Hydrogen combines with nitrogen in a 3:14 weight ratio to form ammonia. If every molecule of ammonia contains three atoms of hydrogen and one atom of nitrogen, an atom of nitrogen must weigh :

Hydrogen combines with oxygen in a 1:8 weight ratio to form water. If every molecule of water contains two atoms of hydrogen and one atom of oxygen, an atom of oxygen must weigh :

When elements react, their atoms combine in :

When $3\ g$ of carbon is burnt in $8\ g$ of oxygen, $11 g$ of carbon dioxide is produced. What mass of carbon dioxide will be formed when $3\ g$ of carbon is burnt in $50\ g$ oxygen?

When $1.375\ g$ of cupric oxide is reduced on heating in a current of hydrogen, the weight of copper remaining $1.098\ g$. In another experiment, $1.179\ g$ of copper is dissolved in nitric acid and resulting copper nitrate converted into cupric oxide by ignition. The weight of cupric oxide formed is $1.476 \ g$. This is in agreement with :

Who stated the law of constant proportion?

A 78.0 g sample of an unknown compound contains 12.4 g of hydrogen.  What is the percent by mass of hydrogen in the compound?