Answer:

Explanation:
First of all we need to calculate the heat that the water in the cooler is able to release:

Where:
- Cp is the mass heat capacity of water
- V is the volume
is the density


To calculate the mass of CO2 that sublimes:

Knowing that the enthalpy of sublimation for the CO2 is: 


Answer:
There are 0.5 mole in 20g of argon.
Explanation:
40 g of argon = 1mole
Then 20g of argon is,
→ 1/40 × 20
→ 0.5 mole
<u>Answer:</u> The uncertainty in the velocity of oxygen molecule is 
<u>Explanation:</u>
The diameter of the molecule will be equal to the uncertainty in position.
The equation representing Heisenberg's uncertainty principle follows:

where,
= uncertainty in position = d = 
= uncertainty in momentum = 
m = mass of oxygen molecule = 
h = Planck's constant = 
Putting values in above equation, we get:

Hence, the uncertainty in the velocity of oxygen molecule is 