How many liters of nitrogen gas is produced if 50.0L of water is produced at STP?

Explanation:

1. Chemical equation

Ammonium nitrite is a solid compound that decomposes into nitrogen gas and water vapor as per this chemical equation:

2. Mole ratio

3. Volume ratio

Since, both species are gases and are at same temperature and pressure, the volume ratio is equal to the mol ratio.

Thus, the volume ratio is:

4. Use the volume ratio with the known amount of water 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.