89.1% Au
The molar mass of Au2O3 is 2(196.97) + 3(16.00) = 441.94 g/mol
The mass percent of Au is therefore 2(196.97) / 441.94, which is 393.94/441.94 = 0.891 —> 89.1%
C is not an example.
explanation: Mass is a physical property as the law of conservation of mass states mass is neither created nor destroyed in a chemical reaction or physical transformation. Chemical reactions are a change in the molecular structure of the product.
A.
This is because BaSO₄ has the lowest solubility product out of all the substances.
Answer:
If the earth's surface is cold, warm air above it will lose heat energy to the cold surface below and the now cool air will remain close to the surface. If a damp surface is warmer than the air above it, some water will evaporate, and the air above the surface will be heated.
Explanation:
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Answer:
- <em>Chemical equations are balanced </em><u>to comply with the law of conservation of mass.</u>
Explanation:
Law of conservation of mass states that matter cannot be either created or destroyed.
A skeleton chemical equation shows the reactants and products of a chemical reaction without taking into account the real proportion in which the reactants combine and the products are obtained.
An example of a skeleton reaction is the combustion of methane:
Such as that equation is shown, there are four atoms of hydrogen in the reactants but only 2 atoms of hydrogen in the products. Also, there are 2 atoms of oxygen in the reactants but three atoms of oxygen in the products. This seems to show that some atoms of hydrogen have been destroyed and some atoms of oxygen have been created. This is impossible as it is against the law of conservation of matter.
Then, to show a real situation, the chemical equation of combustion must be balanced, adjusting the coefficients. This is the balanced chemical equation:
Now you see that the number of atoms of each matter is conserved: the number of carbon atoms in each side is 1, the number of atoms of hydrogen in each side is 4, and the number of atoms of oxygen in each side is 4. Thus, by balancing the chemical equation, the law of conservation of mass is not violated.
