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:
grams KI needed = 31.9 grams
Explanation:
? g KI + 500 g water => 6.0% KI solution
let x = grams KI needed.
Percent = part/total x 100% = (x/x+500)·100% = 6.0%
Solve for 'x' ...
x / x + 500 = 6/100 = 0.06 => x = 0.06(x + 500) => x = 0.06x + 30
x - 0.06x = 30 => 0.94x = 30 => x = 30/0.94 = 31.9 gms KI needed.
Answer:
Nuclear
Explanation:
The material most often used in nuclear power plants is the element uranium. Although uranium is found in rocks all over the world, nuclear power plants usually use a very rare type of uranium, U-235. Uranium is a non-renewable resource. ... Nuclear power plants do not pollute the air or emit greenhouse gases.
Answer:
1. Scientists use experimentation and careful observation to collect evidence to support those explanations. Although there is no single scientific method, all types of scientists use the eight science and engineering practices in different orders and combinations to do their work.
2. In simplest terms, a law predicts what happens while a theory proposes why. A theory will never grow up into a law, though the development of one often triggers progress on the other
3.Data is just data and has no intrinsic meaning on its own. Evidence has to be evidence for or of something; an argument, an opinion, a viewpoint or a hypothesis. The evidence you use depends on your argument.
4.All models have limitations because they are not representative of every possible scenario. They use current knowledge and scientific data, but as those are subject to change, the models based off that knowledge and data are subject to change as well. ... Scientific models are not a replacement for experimentation.
5.What makes a good scientific question is that it can be answered by direct observations or with scientific tools. Examples of questions that are not scientific are based on values or opinions like what people believe is right or wrong, or beautiful or ugly. (to the part that says ANSWER ---->) Scientific ideas change over time as our evidence improves. The more experiments we do and the more data we collect, the better our scientific ideas become. ... When a brand-new idea is suggested, the first step is to collect evidence. But even when that evidence is collected, understanding it can be difficult.
