Answer:

Explanation:
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In this case, since the percent water is computed by dividing the amount of water by the total mass of the hydrate; we infer we first need the molar mass of water and that of the hydrate as shown below:

Thus, the percent water is:

So we plug in to obtain:

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Answer: The pressure of the He is 2.97 atm
Explanation:
According to Dalton's law, the total pressure is the sum of individual pressures.
Given :
=total pressure of gases = 6.50 atm
= partial pressure of Nitrogen = 1.23 atm
= partial pressure of oxygen = 2.3 atm
= partial pressure of Helium = ?
putting in the values we get:
The pressure of the He is 2.97 atm
In descriptive investigations, we still haven't formed any hypothesis yet so we seek information by asking question.
It's not repeatable because repeating the questions over and over again without any clue about what we want to seek is completely waste of time.
Hope this helps xox :)