Answer:
25.2 kJ
Explanation:
The complete question is presented in the attached image to this answer.
Note that, the heat gained by the 2.00 L of water to raise its temperature from the initial value to its final value comes entirely from the combustion of the benzoic acid since there are no heat losses to the containing vessel or to the environment.
So, to obtained the heat released from the combustion of benzoic acid, we just calculate the heat required to raise the temperature of the water.
Q = mCΔT
To calculate the mass of water,
Density = (mass)/(volume)
Mass = Density × volume
Density = 1 g/mL
Volume = 2.00 L = 2000 mL
Mass = 1 × 2000 = 2000 g
C = specific heat capacity of water = 4.2 J/g.°C
ΔT = (final temperature) - (Initial temperature)
From the graph,
Final temperature of water = 25°C
Initial temperature of water = 22°C
ΔT = 25 - 22 = 3°C
Q = (2000×4.2×3) = 25,200 J = 25.2 kJ
Hope this Helps!!!
Answer: Extracellular [Ca2+]
Explanation:
The sensitivity and density of the alpha receptors serve to <em>enhance the response to the release of</em> <em>norepinephrine (NE)</em> . However, they do not exert a strong influence as the concentration of calcium ions on the amount of <em>norepinephrine (NE)</em> released by sympathic nerve terminals.
The release of neurotransmitters depends more on either an external or internal stimulus.This results in an action potential which on reaching a nerve terminal, results in the opening of Ca²⁺ channels in the neuronal membrane. Because the extracellular concentration of Ca²⁺ is greater than the intracellular Ca²⁺ concentration, Ca²⁺ flows into the nerve terminal. This triggers a series of events that cause the vesicles containing <em>norepinephrine (NE)</em> to fuse with the plasma membrane and release <em>norepinephrine (NE)</em> into the synapse. The higher the action potential, the higher the Ca²⁺ flow into the terminals resulting in higher amount of <em>norepinephrine (NE)</em> into the synapse, and vice versa.
Catechol-O-methyltransferase (COMT) is one of several enzymes that degrade catecholamines such as dopamine, epinephrine, and norepinephrine. It serves a regulatory purpose to lower the concentration of norepinephrine upon its release from nerve terminals.
