Density = mass/volume
so rearranged mass = volume x density
mass = 8.920 x 45 = 401.4g
rearrange (there are 1000grams in 1kg)
volume = mass/density
volume = 1000/8.920
volume = 112.1076233cm3
Answer: New pressure inside the flask would be 148.8 kPa.
Explanation: The combined gas law equation is given by:

As the flask is a closed flask, so the volume remains constant. Temperature is constant also.
So, the relation between pressure and number of moles becomes



- Final conditions: When additional 3 puffs of air is added

Putting the values, in above equation, we get

The metric system is based on powers of 10 so it is much easier to convert units, often just by moving the decimal point.
Answer:
5.7 pH
Explanation:
To find pH when given [H+], you use this formula: pH = -log[H+]
-log * 2.1e-6 = 5.6778 = 5.7 pH