Answer:

Explanation:
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In this case, according to this calorimetry problem on equilibrium temperature, it is possible for us to infer that the heat released by the metal allow is absorbed by the water for us to write:

Thus, by writing the aforementioned in terms of mass, specific heat and temperature, we have:

Then, we solve for specific heat of the metallic alloy to obtain:

Thereby, we plug in the given data to obtain:

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Antimony has two naturally occurring isotopes. Their abundance is given in the pic attached below
The partial pressure of 0.50 Ne gas is 214.71 torr
calculation
the partial pressure of Ne = moles of Ne/total moles x final pressure
find the total moles of the air mixture
that is moles of Ne + moles of K= 0.50 + 1.20 = 1.70 moles
The partial pressure is therefore = 0.50 /1.70 x 730 = 214.71 torr
Answer:
62.5 moles of O₂.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
2C₈H₁₈ + 25O₂ —> 16CO₂ + 18H₂O
From the balanced equation above,
2 moles of C₈H₁₈ reacted with 25 moles of O₂.
Finally, we shall determine the number of mole of O₂ needed to react with 5 moles of C₈H₁₈. This can be obtained as shown below:
From the balanced equation above,
2 moles of C₈H₁₈ reacted with 25 moles of O₂.
Therefore, 5 moles of C₈H₁₈ will react with = (5 × 25) / 2 = 62.5 moles of O₂.
Thus, 62.5 moles of O₂ is needed for the reaction.