Answer: -
1.34 L
Explanation: -
Initial Pressure P 1 = 39.1 bar
Initial Temperature T 1 = 643 K
Let the initial volume be V 1.
Final pressure P 2 = 87.0 bar
Final temperature T 2 = 525 K.
Final volume V 2 = 0.492 L
Using the equation


Plugging in the values
We have
V 1 = 87 bar x 0.492 L x 643 K / (39.1 bar x 525 K)
= 1.34 L
Thus, a gas is contained in a thick-walled balloon. When the pressure changes from 39.1 bar to 87.0 bar the volume changes from 1.34 L to 0.492L and the temperature changes from 643K to 525K
4.67 is the right answer
+ − − log(7,5 ∗ 10−3) − log(6.2 ∗ 10−8) ,34 ,24
= 2 = 2 =4.67
Answer: -
6.26 grams
Explanation: -
Atomic Mass of sodium Na = 23 gram
Mass of Na = 18 g
Atomic mass of oxygen O = 16 gram
Molar mass of O2 = 16 x 2 = 32 gram
The balanced chemical equation for the reaction is
4 Na + O2 -- > 2 Na 2 O
From the balanced chemical equation, we see
4 Na requires 1 O2
4 x 23 gram of Na requires 32 gram of O2
18 g of Na gives

= 6.26 grams of O2
For the reaction of formation of Na2O, for 18.0 g of Na, 6.26 grams of O2 are needed for reaction.