Answer:
62.07 %
Explanation:
Chemical Formula = (CH3)2CO = C3H6O
Mass of C = 12 g/mol
Mass of H = 1 g/mol
Mass of O = 12 g/mol
Mass of C3H6O = 3(12) + 6(1) + 16 = 58 g/mol
Total mass of C in Acetone = 12 * 3 = 36 g
Mass Percent of C = Total mass of C / Mass of Acetone * 100
Mass percent = 36 / 58 * 100
Mass percent = 62.07 %
This problem is providing us with the chemical equation for the decomposition of water to hydrogen and oxygen, the involved bond energies and asks for the total energy of the reaction as well as whether it is endothermic or exothermic. At the end, one comes to the conclusion that it is exothermic because the total energy is -425 kJ.
<h3>Bond energy:</h3>
In chemistry, bond energies are defined as the necessary energy to break a bond between two atoms. In this case, we see that water, H2O has two H-O bonds and hydrogen and oxygen have two H-H and one O=O bonds, respectively.
Thus, we write the following heat equation, which comprises the aforementioned bond energies and the stoichiometric coefficients in the reaction:
Hence, we plug in the given bond energies to obtain:
Where the negative suggests this is an exothermic reaction as it releases energy (negative enthalpy).
Learn more about bond energies: brainly.com/question/26141360
Answer:
the properties of three undiscovered elements is the correct answer.
Explanation:
After he completed his work Mendeleev predicted the properties of the undiscovered elements.
In the year 1871, Dmitri Mendeleev predicted the detailed existence and the properties of the three elements that are undiscovered and he gained tremendous fame.
He left the gap in the table to put the elements which are not identified at that time and by glancing at the physical and chemical properties of an element next to the gap, Mendeleev could predict the properties of the not discovered elements.
Chromosomes have hereditary function
that are capable of self-duplication and they have thread-like structures seen
inside the nucleus of plant and animal. In plants, they go through a cycle
called alteration of generation that has multicellular stages. One is sporophyte
that is a diploid, and the other is gametophyte with a haploid.
<span>Moreover, spores are produce through
meiosis so it go through a process of chromosome reduction in order to create a
haploid spores. While, gametes undergo mitosis and the structure is already a haploid,
which means that the number of chromosomes will not change in order to produce
haploid. In this case, the plant have both spores and gametes and the
similarities is that, they are both singles celled and a haploid. Therefore,
the number of the chromosome in the gametophyte generation is also 32.</span>
