The reaction 2N2O5 (g) → 2N2O4 (g) + O2 (g) has a reaction rate that is dependent only on the concentration of N2O5 and at a certain temperature has a rate constant k of 0.0168 s-1. If 2.50 moles of N2O5 were placed in a 5.00 liter container at that temperature, how many moles of N2O5 would remain after 1.00 min?

0.910 mol

Explanation:

Let's consider the following reaction.

2 N₂O₅(g) → 2 N₂O₄(g) + O₂(g)

This reaction is of first order with respect to N₂O₅, with a rate constant k = 0.0168 s⁻¹.

We can calculate the concentration at a certain time using the following expression.

where,

The initial concentration of N₂O₅ is:

2.50 mol / 5.00 L = 0.500 M

The concentration of N₂O₅ after 1.00 min (60 s) is:

The moles of N₂O₅ after 1.00 min are:

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.