<u>Answer:</u> The new pressure for oxygen gas is 6 atm.
<u>Explanation:</u>
To calculate the new pressure of the gas, we use the equation given by Boyle's Law.
This law states that the pressure is inversely proportional to the volume of the gas at constant temperature and number of moles.
Mathematically,

or,

where,
are the initial pressure and volume of the gas.
are the final pressure and volume of the gas.
We are given:

Putting values in above equation, we get:

Hence, the new pressure for oxygen gas is 6 atm.
Answer:
The 1st and 2nd ones on the top
Explanation:
Hope this helps:)
A nitrogen atoms can make 3 covalent bonds because it has three unpaired electrons
If 0.5 L of solution contains 4 mol
then let 1 L of solution contain x mol
⇒ (0.5 L) x = (4 mol) (1 L)
x = (4 mol · L) ÷ (0.5 L)
x = 8 mol
Thus the molarity of the Sodium Chloride solution is 8 mol / L OR 8 mol/dm³.