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The initial mass of
Magnesium Sulfate Heptahydrate (MgSO₄·7H₂O) is 23,08 g
The chemical reaction for the dehydrating of
Magnesium Sulfate Heptahydrate (MgSO₄·7H₂O) is the following:
MgSO₄·7H₂O(s) + Δ → MgSO₄(s) + 7H₂O(g)
We know that the sample loses 11,80 g upon heating.
That mass is the mass of Water that is released as vapor. Knowing that piece of information, we can apply the following conversion factor to go from the mass of water to the moles of water and back to the mass of the original compound (mi).

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Answer:
Helium, this noble gas has the least density at STP
Explanation:
Answer:
A sample of a gas (5.0 mol) at 1.0 atm is expanded at constant temperature from 10 L to 15 L. The final pressure is 0.67 atm.
Step by Step Explanation?
Boyle's law states that in constant temperature the variation volume of gas is inversely proportional to the applied pressure.
The formula is,
P₁ x V₁ = P₂ × V₂
Where,
P₁ is initial pressure = 1 atm
P2 is final pressure = ? (Not Known)
V₁ is initial volume = 10 L
V₂ is final volume = 15 L
Now put the values in the formula,
\begin{gathered}\rm 1\times 10 = P_2\times 15\\\\\rm P_2 = \frac{10}{15\\} \\\\\rm P_2 = 0.67\end{gathered]
Therefore, the answer is 0.67 atm.
<span><span>Mn<span>O<span>2<span>(s)</span></span></span>+<span>H<span>2<span>(g)</span></span></span>→Mn<span>O<span>(s)</span></span>+<span>H2</span><span>O<span>(g)</span></span></span></span>