Answer: The correct option is (c). The total pressure doubles.
Solution:
Initially, only 4 moles of oxygen gas were present in the flask.
() ( according to Dalton's law of partial pressure)
....(1)
= Total pressure when only oxygen gas was present.
Final total pressure when 4 moles of helium gas were added:
partial pressure of oxygen in the mixture :
Since, the number of moles of oxygen remains the same, the partial pressure of oxygen will also remain the same in the mixture.
= Total pressure of the mixture.
from (1)
On rearranging, we get:
The new total pressure will be twice of initial total pressure.
B- Predict the damages due to an earthquake
Answer is: carbon dioxide (CO₂) can affect the end point of the titration.
Carbon dioxide, or carbon(IV) oxide, reacts with water and form carbonic acid, which can affect the end point of the titration, because more base is needed for neutralization of partially neutralized stomach acid.
Balanced chemical reaction of carbon dioxide and water: CO₂ + H₂O → H₂CO₃.