At 650mm hg, a gas has a volume of 190l, what is its volume at standard pressure

Answer : The volume of the gas at standard pressure (1 atm) is, 162.45 L

Solution : Given,

Initial pressure of gas = 650 mmHg =    

Initial volume of gas = 190 L

Final pressure of gas = 1 atm     (standard pressure is 1 atm)

Formula used :

where,

= initial pressure of gas

= final pressure of gas

= initial volume of gas

= final volume of gas

Now put all the given values in the above formula, we get

By rearranging the terms, we get the final volume of the gas.

Therefore, the volume of the gas at standard pressure (1 atm) is, 162.45 L

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.