2H2 + O2 2H2O How many moles of water can be produced if 8 moles He are used?

a.2
b.4
c.8
d.16

c ) 8

Explanation:

Given data:

Number of moles of water produced = ?

Moles of hydrogen react = 8 mol

Solution:

Chemical equation:

2H₂ + O₂     →     2H₂O

Now we will compare the moles of hydrogen and water.

         H₂          :         H₂O

          2          :            2

         8           :           8

Thus, 8 moles of water will produced.

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.