Answer:
The answer to your question is pH = 6.3
Explanation:
Data
pH = ?
[H⁺] = 4.73 x 10⁻⁷ M
pH is the measure of the concentration of [H⁺]. pH measures the acidity of the solution. If the value of pH is between 0 and 6.9, the solution is an acid. If the pH is 7.0 the solution is neutral and if the pH is between 7.1 and 14, the solution is an alkali.
Formula
pH = -log[H⁺]
Substitution
pH = -log[4.73 x 10⁻⁷]
-Simplification
pH = - (-6.3)
-Result
pH = 6.3
<u>Answer:</u> The correct answer is geographical map.
<u>Explanation:</u>
Model is defined as the three dimensional representation of a proposed structure in a smaller scale.
For the given options:
<u>Option 1:</u> PV = nRT
This is a proposed law. This law is known as ideal gas law. A law is defined as the rule which defined a correct procedure. For any gas behaving ideally, this law is used.
<u>Option 2:</u> Geographical map
Map is defined as the diagrammatic representation of an area of land or sea which also shows physical features, roads, cities etc..
A 3-D model can be prepared for geographical map.
<u>Option 3:</u> I believe that aliens exist
This is a hypothetical statement. It is a smart guess by the means of set of assumptions and observations. For its validation, we need to conduct some experiments.
Hence, the correct answer is geographical map.
Answer: +178.3 kJ
Explanation:
The chemical equation follows:

The equation for the enthalpy change of the above reaction is:
![\Delta H^o_{rxn}=[(1\times \Delta H^o_f_{(CaO(s))})+(1\times \Delta H^0f_{CO_2}]-[(1\times \Delta H^o_f_{(CaCO_3(s))})]](https://tex.z-dn.net/?f=%5CDelta%20H%5Eo_%7Brxn%7D%3D%5B%281%5Ctimes%20%5CDelta%20H%5Eo_f_%7B%28CaO%28s%29%29%7D%29%2B%281%5Ctimes%20%5CDelta%20H%5E0f_%7BCO_2%7D%5D-%5B%281%5Ctimes%20%5CDelta%20H%5Eo_f_%7B%28CaCO_3%28s%29%29%7D%29%5D)
We are given:

Putting values in above equation, we get:
![\Delta H^o_{rxn}=[(1\times (-635.1))+(1\times (-393.5))]-[(1\times (-1206.9))]](https://tex.z-dn.net/?f=%5CDelta%20H%5Eo_%7Brxn%7D%3D%5B%281%5Ctimes%20%28-635.1%29%29%2B%281%5Ctimes%20%28-393.5%29%29%5D-%5B%281%5Ctimes%20%28-1206.9%29%29%5D)
The DH°rxn for the decomposition of calcium carbonate to calcium oxide and carbon dioxide is +178.3 kJ
i think that it is the tree
An element is all the same thing. Pure, if you will.
The first one is definitely an element. The second would be a compound (it's atoms are different colors). I would say the last one is an element, since it has ll the same color of atoms.
I hope this helped you! If you have anymore questions, feel free to ask me.