<span>The correct answers are A, B, and D. The ΔHrxn is equal to the ΔHf when the ΔHf of the reactants is zero, and this can only occur when the reactants are pure elements (not compounds) in their natural phase at ambient temperature.
c) Chlorine's natural phase is gaseous, but since it is a liquid in this reaction, ΔHf ≠ 0.
e) CO is a compound, not a pure element.
f) BaCO3 is a compound, not a pure element.</span>
A compound was found to be soluble in water. It was also found that addition of acid to an aqueous solution of this compound resulted in the formation of carbon dioxide. Which one of the following cations would form a precipitate when added to an aqueous solution of this compound?
Options
a. NH4
b. K
c. Cr
d. Rb
e. Na
Answer: c: Cr
Explanation:
The aforementioned reaction are banters for to distract ones focus from the question.
However it should be noted that
Cr can be found in tannery waste water showing that it can be soluble in water.
The carbonate compound when reacting with acid CO_2 evolves.
Focusing on the cation that would form a precipitate when added to an aqueous solution.
Chemical precipitation method is a common method for to remove chromium and to recover it from tannery wastewater.
Cr would form a precipitate.
Answer:
As a river flows, it picks up sediment from the river bed, eroding banks, and debris on the water. The river mouth is where much of this gravel, sand, silt, and clay—called alluvium—is deposited. When large amounts of alluvium are deposited at the mouth of a river, a delta is formed.
Explanation:
How much protein one should obtain from diet
Answer:
4 gram
