Answer:
The pressure is 0, 63 atm
Step-by-step explanation:
We use Boyle Mariotte's formula: for a given mass of gas at constant temperature, the pressure and volume vary inversely proportionally:
P1xV1= P2xV2
P2=(P1xV1)/V2= (0,8 atmx 12, 2 L)/15, 6 L=0,63 atm