Why is respiration an exothermic reaction? A. a large amount of energy is released into its surroundings B. the heat content, q,
of the reaction is positive C. a large amount of energy is required to activate the reaction D. there is no exchange of energy between the system and the surrounding
2 answers:
A. a large amount of energy released into its surrounding
During the respiration, glucose molecules are converted to other molecules in a series of steps. They finally end up as as carbon-dioxide and water.
The overall reaction is
<span>C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + 2805 kJ
</span>
The reaction is exothermic reaction because <span>C=O and O-H bonds in the products are so much more stable than the bonds in the reactants.
</span>
Bond energy is the average needed to break a bond.
Some bond energies are:
C-C = 347 kJ/mol
C-H = 413kJ/mol;
C-O = 358 kJ/mol;
O-H = 467 kJ/mol;
O=O = 495 kJ/mol;
<span>C=O = 799 kJ/mol</span>
During the respiration, glucose molecules are converted to other molecules in a series of steps. They finally end up as as carbon-dioxide and water.
The overall reaction is
<span>C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + 2805 kJ
</span>
The reaction is exothermic reaction because <span>C=O and O-H bonds in the products are so much more stable than the bonds in the reactants.
</span>
Bond energy is the average needed to break a bond.
Some bond energies are:
C-C = 347 kJ/mol
C-H = 413kJ/mol;
C-O = 358 kJ/mol;
O-H = 467 kJ/mol;
O=O = 495 kJ/mol;
<span>C=O = 799 kJ/mol</span>
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Answer:
1) 883 kgm2
2) 532 kgm2
3) 2.99 rad/s
4) 944 J
5) 6.87 m/s2
6) 1.8 rad/s
Explanation:
1)Suppose the spinning platform disk is solid with a uniform distributed mass. Then its moments of inertia is:
If we treat the person as a point mass, then the total moment of inertia of the system about the center of the disk when the person stands on the rim of the disk:
2) Similarly, he total moment of inertia of the system about the center of the disk when the person stands at the final location 2/3 of the way toward the center of the disk (1/3 of the radius from the center):
3) Since there's no external force, we can apply the law of momentum conservation to calculate the angular velocity at R/3 from the center:
4)Kinetic energy before:
Kinetic energy after:
So the change in kinetic energy is: 2374 - 1430 = 944 J
5)
6) If the person now walks back to the rim of the disk, then his final angular speed would be back to the original, which is 1.8 rad/s due to conservation of angular momentum.
