Suppose there is a gaseous mixture of nitrogen and oxygen. If the total pressure of the mixture is 470 mmHg , and the partial pressure of nitrogen is 280 mmHg , calculate the partial pressure of oxygen in the mixture using Dalton's law.

190 mmHg

Explanation:

According to Dalton's law, in a mixture of ideal gases, each gas behaves independently of the other. Also, the total pressure is equal to the sum of the individual partial pressures.

The total pressure of the mixture is 470 mmHg , and the partial pressure of nitrogen is 280 mmHg. Then,

P = pO₂ + pN₂

pO₂ = P - pN₂

pO₂ = 470 mmHg - 280 mmHg

pO₂ = 190 mmHg

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.