Answer:
Conclusion
Explanation:
I believe you were asking for the term that best matches with the description given. Typically the conclusion summarizes your experiment in a 1 to 2 paragraph format.
A student builds a model of a race car. The scale is 1:15. In the scale model, the car is 8 cm tall. How tall is the actual car?
<h2>Answers:</h2>
<h3>A. 120 cm</h3>
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<span>0.925 grams if using hydrochloric acid in the reaction.
0.462 grams if using sulfuric acid in the reaction.
0.000 grams if using nitric acid in the reaction.
Assuming you're using HCl or a similar acid for this reaction, the equation for the reaction is:
Zn + 2 HCl ==> ZnCl2 + H2
So each mole of zinc used, produces 1 mole of hydrogen gas, or 2 moles of hydrogen atoms. So we need to look up the atomic weights of both zinc and hydrogen.
Atomic weight zinc = 65.38
Atomic weight hydrogen = 1.00794
Moles zinc = 30.0 g / 65.38 g/mol = 0.458855919 mol
Since we produce 2 moles of hydrogen atoms per mole of zinc, multiply by 2 and the atomic weight of hydrogen to get the mass of hydrogen produced. So
0.458855919 * 2 * 1.00794 = 0.92499847 grams.
Rounding to 3 significant figures gives 0.925 grams.
To show the assumption of the acid used, the balanced equation for sulfuric acid would be
Zn2 + H2SO4 ==> Zn(SO4)2 + H2
Which means that for every mole of zinc used, 1 mole of hydrogen gas is generated (half that produced via hydrochloric acid).
If nitric acid were used, the reaction is
4Zn + 10HNO3 ==> 4Zn(NO3)2 + N2O + 5H2O
Which means that NO hydrogen gas is generated.
The only justification for assuming hydrochloric acid is used is that it's a fairly common acid that's easy to obtain. But as shown above with 2 alternative acids, the amount of hydrogen gas generated is very dependent upon the exact chemical reaction occurring and asking "How many grams of hydrogen are produced if 30.0 g of zinc reacts?" is a rather silly question unless you specify EXACTLY what the reaction is.</span>
Answer:
Option B. is the right answer.
Explanation:
Before developing a new technology, an engineer has to evaluate the advantages and disadvantages of the chemical used in order to clean water bodies. If the chemical has more disadvantages as compared to advantages, so its usage will be avoided while if the chemical does not harm the marine organisms of the ocean so it can be used for the purpose of cleaning. So we can say that first the engineer has to study the chemicals.
Answer:
As a substance changes from a solid to a liquid to a gas, its molecules first the molecules are moving fast enough, they are able to "escape." They leave the surface of the liquid as gas molecules. Evaporation is not the only process that can change a substance from a liquid to a gas. The same change can occur through boiling.
Explanation:
