Question

When oxygen and hydrogen combine chemically, the mass of the product is.

Answer 1

Answer:

The problem tells you that

6 g

of hydrogen gas,

H

2

, react with an unknown mass of oxygen gas,

O

2

, to form

54 g

of water.

As you know, the law of mass conservation tells you that the in a chemical reaction the total mass of the reactants must be equal to the total mass of the products.

In your case, this can be written as

total mass of reactants



m

H

2

+

m

O

2

=

mass of product



m

H

2

O

This means that the reaction must have consumed

m

O

2

=

m

H

2

O

−

m

H

2

m

O

2

=

54 g

−

6 g

=

48 g O

2

Explanation:

I'll show you two approaches to solving this problem, one really short and one relatively long.