A compound is a pure substance composed of two or more different atoms chemically bonded to one another. A compound can be destroyed by chemical means. It might be broken down into simpler compounds, into its elements or a combination of the two.
The
equation for the photosynthesis reaction in which carbon dioxide and water
react to form glucose is .
The hear reaction is the difference between the bond dissociation energies in
the products and the bond dissociation energies of the reactants
The
reactant molecules have 12 C = O, 12 H - O bonds while the product molecules
have 5 C - C, 7 C – O, 5 H – O, and 6 O = O bonds. The average bond
dissociation energies for the bonds involved in the reaction are 191 for C = O,
112 for H – O, 83 C –C, 99 C – H, 86 C – O, 119 O = O.
Substitute
the average bond dissociation energies in the equation for and
calculate as follows
=
[12 (C=O) + 12 (H-O)] – [5(C-C) + 7(C-H) + 7 (C-O) + 5(H-O) + 6(O=O)]
=
[12x191 kcal/mol + 12x112 kcal//mol] – [5x83 kcal/mol + 7x99 kcal/mol + 7x86
kcal/mol + 5x112 kcal/mol + 6x119 kcal/mol]
=
3636 kcal/mol – 2984 kcal/mol = 652 kcal/mol x 4.184 Kj/1kcal = 2.73x10^3 kJ/mol
So,
enthalpy change for the reaction is 652 kcal/mol or 2.73x10^3 kJ/mol
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Answer:
D.
Explanation:
Water is polar, for one thing. Polar mixes with polar, nonpolar mixes wih nonpolar. This leaves D.
Most transition metal form more than one cation but aluminum forms the Al3+ cation only.
Answer:
The answer to your question is below
Explanation:
Covalent bonds are bonds between to atoms that share a pair of electrons, there are three kinds of covalent bonds but I'll describe only two:
Covalent non polar bond: is a covalent bond between two elements of the same element. Ex two hydrogens, two chlorine, two oxygenes, etc.
Covalent polar bond: is a covalent bond between 2 elements of different elements, for example: hydrogen and chlorine or nitrogen, they are polar because on of the element that form it is smaller than the other one, then a partial positive and a partial negative charge is formed.