Answer:
40 mL
Explanation:
According to Boyle's law at a given constant temperature and amount of gas the product of it's pressure and volume is constant (or) Pressure is inversely proportional to its volume at a given temperature and amount of gas.
PV=constant.(At a given Temperature and no of moles ).
now we are given a gas with initial pressure [tex]P_{in}=4 atm\\V_{in}=20mL\\P_{final}=2atm\\[/tex] now we are required to find out the final volume of the gas
Using PV=Constant;
[tex]P_{in}\times V_{in}=P_{final}\times V_{final}\\[/tex]
substituting in the above equation we get 20*4=V*2 which implies V =40 mL
