2.168 L of air will leave the container as it warms
<h3>Further explanation</h3>
Given
V₁=2.05 L
T₁ = 5 + 273 = 278 K
T₂ = 21 + 273 = 294 K
Required
Volume of air
Solution
Charles's Law
When the gas pressure is kept constant, the gas volume is proportional to the temperature

Input the value :
V₂=(V₁.T₂)/T₁
V₂=(2.05 x 294)/278
V₂=2.168 L
Answer:
7.71x10^23 molecules
Explanation:
Avogadro's # = 6.022x10^23
1.28 mol SiO2 x 6.022x10^23/ 1 mol SiO2 = 7.71x10^23 molecules