Answer:
N₂+3H₂ ⇄2NH₃ is a thermochemical reaction whereas A+BC⇄AB is not.
A+BC⇄AB is a reaction of pure a element with a compound while N₂+3H₂ ⇄2NH₃ is a reaction between two pure elements.
Explanation:
Let A+BC⇄AB be equation i and N₂+3H₂ ⇄2NH₃ be equation ii.
The two reactions differ in that ii is a thermo-chemical reaction whereas i is not. This is because energy is included in reaction ii but not included in reaction i.
Also i is a reaction of pure a element with a compound while ii is a reaction between two pure elements. The compound is BC while the pure element is A.
C, erosion. Erosion is the natural process of breaking down natural products through wind, or similar natural resources.
Answer: 
Explanation:
pH or pOH is the measure of acidity or alkalinity of a solution.
pH is calculated by taking negative logarithm of hydrogen ion concentration.
![pH=-\log [H^+]](https://tex.z-dn.net/?f=pH%3D-%5Clog%20%5BH%5E%2B%5D)
Putting in the values:
![5.29=-log[H^+]](https://tex.z-dn.net/?f=5.29%3D-log%5BH%5E%2B%5D)
![[H^+]=5.1\times 10^{-6}](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3D5.1%5Ctimes%2010%5E%7B-6%7D)
Thus ![[H^+]](https://tex.z-dn.net/?f=%5BH%5E%2B%5D)
is
The correct answer is 2.53 g of precipitate, BaCrO4.
<span>Answer: B. Ionic solids have higher melting points than molecular solids.
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This is because the rest are false, as solids are able to melt, and do have melting points. Also, not all solids have the same melting points.
