Asample of gas y occupies 500l at the pressure of 80 kpa . after changing the volume of the sample, the pressure of it is 400 kpa. what is the new volume of the gas

The  new  volume  of  the  gas   is calculated using the Boyles  law  formula
that is P1V1=P2V2
P1=80  kpa
V1=  500 L
P2=400Kpa
V2=?

by  making V2  the  subject of  the  formula    V2 =P1V1/P2

=(500 L  x80  KPa)/400  KPa  =  100  L    is the new  volume  of  the  gas

The activity series is shown in the attached picture. if the element is below the other, then you can displace the other. following the activity series as a guide, the reactions are as follows: nickel and aluminum chloride3 ni + 2 alcl₃  → 3 nicl₂ + 2 albarium and copper bromideba + cubr  →  no reaction because cu is less oxidizable than bapotassium nitrate and aluminum3 kno₃ + al  → al(no₃)₃ + 3 ksodium phosphate and zincnaso₄ + zn  → znso₄ + na

Sorry i dont understand the question can you rephase it?