Answer:
using bond energies = - 37 kJ
using enthalpies of formation = - 45.7 kJ
Explanation:
From the reaction;
CH2═CH2(g) + H2O(g) -------> CH3CH2OH(g)
From the above reaction; there are 4 (C-H) bonds , 1 ( C=C) and 2 (H-O) of ethene which forms 5(C-H) bonds, 1 (C-C) and 1 (C-O) and 1(H-O) bonds.
Using Bond Energies; the heat of the reaction can be written as:
∑ energy of old bond breaking + ∑ energies of the new bond formation.
∑ ![[(4 * BE_{C-H}) + BE_{C-C}) + + BE_{O-H})]](https://tex.z-dn.net/?f=%5B%284%20%2A%20BE_%7BC-H%7D%29%20%20%2B%20BE_%7BC-C%7D%29%20%2B%20%20%2B%20BE_%7BO-H%7D%29%5D)
+ ∑ ![[(5 * BE_{C-H}) + BE_{C-C}) + BE_{O-H}+ BE_{C-O})]](https://tex.z-dn.net/?f=%5B%285%20%2A%20BE_%7BC-H%7D%29%20%2B%20BE_%7BC-C%7D%29%20%2B%20BE_%7BO-H%7D%2B%20BE_%7BC-O%7D%29%5D)
∑![[4*413 kJ)+(614kJ)+(2*647kJ]](https://tex.z-dn.net/?f=%5B4%2A413%20kJ%29%2B%28614kJ%29%2B%282%2A647kJ%5D)
+ ∑ ![(5*-413kJ)+(-347kJ)+(-467kJ)+(-358kJ)]](https://tex.z-dn.net/?f=%285%2A-413kJ%29%2B%28-347kJ%29%2B%28-467kJ%29%2B%28-358kJ%29%5D)
-37 kJ
To calculate the heats of reaction by using enthalpies of formation; we have:
∑ 
- ∑ 
∑ 
- ∑ 
(-235.1 kJ) - [(+52.47 kJ) + (-241.826 kJ)]
-45.7 kJ
Answer:
-12162.47 joules (or -12000 joules when accounting for significant figures)
Explanation (btw I used 1 cal as 4.184 joules because SI units are better):
q = m c delta T
q = (70.9) (4.184) (25 - 66)
q = (70.9) (4.184) (-41)
q = -12162.47 joules
The chemical formula for chlorophyll is C55H72O5N4<span>Mg. Only 1 of the 137 atoms comes from magnesium.
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Answer:
The strength of an acid or alkali depends on the degree of dissociation of the acid or alkali in water. The degree of dissociation measures the percentage of acid molecules that ionise when dissolved in water. He could use universal indicators or litmus paper for this.
Explanation:
(See answer for the explanation)
Answer:
B. two rounds of cell division
