A sample of gas has a volume of 400 liters when its temperature is 20.C and its pressure is 300.mm of Hg. What volume will the gas occupy at STP?

V₂ = 145.35 L

Explanation:

Given data:

Initial volume = 400 L

Initial pressure = 300 mmHg (300/760 =0.39 atm)

Initial temperature = 20 °C (20 +273 = 293 K)

Final temperature = 273 K

Final volume = ?

Final pressure = 1 atm

Solution:

Formula:  

P₁V₁/T₁ = P₂V₂/T₂  

P₁ = Initial pressure

V₁ = Initial volume

T₁ = Initial temperature

P₂ = Final pressure

V₂ = Final volume

T₂ = Final temperature

P₁V₁/T₁ = P₂V₂/T₂  

V₂ = P₁V₁T₂  /T₁ P₂

V₂ =  0.39 atm × 400 L × 273 K / 293 K × 1 atm

V₂ = 42588 atm.L.K /293 K.atm

V₂ = 145.35 L

answer : one can design an experiment using a liquid and an additive that can be added to the liquid and observe the chemical changes in the reaction species.

one would need a beaker which is filled with a known amount of the liquid in which thermometer is placed to measure the temperature changes; after addition of the additive to the liquid solution one can note down the temperature change and find whether the reaction is endothermic or exothermic in nature. by subtracting the initial temperature value with the final temperature one can find the temperature changes.

various combinations of liquid and additive can be used. liquid in this case can be a known quantity of water and additives can be epsom salt or without epsom salt the experiment can be conducted to notice the changes. water and ice, hydrogen peroxide and dry yeast, vinegar and baking soda,etc.