Answer:- New pressure is 0.942 atm.
Solution:- The volume of the glass bottle would remain constant here and the pressure will change with the temperature.
Pressure is directly proportional to the kelvin temperature. The equation used here is:

Where,
and
are initial and final temperatures,
and
are initial and final pressures.
= 20.3 + 273.15 = 293.45 K
= -2.0 + 273.15 = 271.15 K
= 1.02 atm
= ?
Let's plug in the values in the equation and solve it for final pressure.


= 0.942 atm
So, the new pressure of the jar is 0.942 atm.
464 g radioisotope was present when the sample was put in storage
<h3>Further explanation</h3>
Given
Sample waste of Co-60 = 14.5 g
26.5 years in storage
Required
Initial sample
Solution
General formulas used in decay:

t = duration of decay
t 1/2 = half-life
N₀ = the number of initial radioactive atoms
Nt = the number of radioactive atoms left after decaying during T time
Half-life of Co-60 = 5.3 years
Input the value :

Answer:
The mole fraction of ethanol is 0.6. A 10 mL volumetric pipette must be used for to measure the 10 mL of ethanol. The vessel should be clean and purged.
Explanation:
For calculating mole fraction of ethanol, the amount of moles ethanol must be calculated. Using ethanol density (0.778 g/mL), 10 mL of ethanol equals to 7.89 g of ethanol and in turn 0.17 moles of ethanol. The same way for calculate the amount of water moles (ethanol density=0.997 g/mL). 2 mL of water correspond to 0.11. The total moles are: 0.17+0.11=0.28. Mole fraction alcohol is: 0.17/0.28=0.6