I think it’s light
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Answer:
2.8x10^24
Explanation:
To convert moles to molecules, multiply the number of moles by Avagadro's number (6.02x10^23. Round if required.
4.62mol × 6.02x10^23 = 2.8x10^24
Answer:
3.67 moles of N
Explanation:
The epinephrine's chemical formula is: C₉H₁₃O₃N
We were told that a chemist found that in a mesaure of epinephrine, he found 33 moles of C
We must know that 9 moles of C are in 1 mol of C₉H₁₃O₃N so, let's make a rule of three:
If 9 moles of C are found in 1 mol of C₉H₁₃O₃N
Therefore 33 moles of C must be found in (33 .1) / 9 = 3.67 moles of C₉H₁₃O₃N
There is a second rule of three, then.
In 1 mol of C₉H₁₃O₃N we have 1 mol of N
Then, 3.67 moles C₉H₁₃O₃N must have (3.67 . 1) / 1 = 3.67 moles of N
Remember 1 mol of C₉H₁₃O₃N has 9 moles of C, 13 moles of H, 3 moles of O and 1 mol of N
We write DE = q+w, where DE is the internal energy change and q and w are heat and work, respectively.
(b)Under what conditions will the quantities q and w be negative numbers?
q is negative when heat flows from the system to the surroundings, and w is negative when the system does work on the surroundings.
As an aside: In applying the first law, do we need to measure the internal energy of a system? Explain.
The absolute internal energy of a system cannot be measured, at least in any practical sense. The internal energy encompasses the kinetic energy of all moving particles in the system, including subatomic particles, as well as the electrostatic potential energies between all these particles. We can measure the change in internal energy (DE) as the result of a chemical or physical change, but we cannot determine the absolute internal energy of either the initial or the final state. The first law allows us to calculate the change in internal energy during a transformation by calculating the heat and work exchanged between the system and its surroundings.
