C. the denser the plants the better.
Answer:
C
In the reaction of silver nitrate with copper metal, metallic silver comes out of solution, and the solution turns blue. This as a <u>single replacement</u> reaction.
<h3>What is
single replacement reaction?</h3>
A single replacement reaction, also known as a single displacement reaction, occurs when one element in a molecule is swapped out for another. The starting materials are always pure elements, such as a pure zinc metal or hydrogen gas, plus an aqueous compound.
A + BC → B + AC
When A is more reactive than B or when the product AC is more stable than BC, single replacement reactions happen. A and B could either be two halogens or two metals (with hydrogen included) (C is a cation). C functions as a spectator ion when BC and AC are in aqueous solutions.
For example, 2HCl(aq)+Zn(s)→ZnCl₂(aq)+H₂(g)
Learn more about single replacement reactions here:
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Explanation:
Calcium carbonate (Chalk) is a chemical compound, with the chemical formula CaCO3. Calcium carbonate (Chalk) is a chemical compound, with the chemical formula CaCO3.
The mass of ammonium chloride that must be added is : ( A ) 4.7 g
<u>Given data :</u>
Volume of water ( V ) = 250 mL = 0.25 L
pH of solution = 4.85
Kb = 1.8 * 10⁻⁵
Kw = 10⁻¹⁴
Given that the dissolution of NH₄Cl gives NH₄⁺⁺ and Cl⁻ ions the equation is written as :
NH₄CI + H₂O ⇄ NH₃ + H₃O⁺
where conc of H₃O⁺
[ H₃O⁺ ] = 
and Ka = Kw / Kb
∴ Ka = 5.56 * 10⁻¹⁰
Next step : Determine the concentration of H₃O⁺ in the solution
pH = - log [ H₃O⁺ ] = 4.85
∴ [ H₃O⁺ ] in the solution = 1.14125 * 10⁻⁵
Next step : Determine the concentration of NH₄CI in the solution
C = [ H₃O⁺ ]² / Ka
= ( 1.14125 * 10⁻⁵ )² / 5.56 * 10⁻¹⁰
= 0.359 mol / L
Determine the number of moles of NH₄CI in the solution
n = C . V
= 0.359 mol / L * 0.25 L = 0.08979 mole
Final step : determine the mass of ammonium chloride that must be added to 250 mL
mass = n * molar mass
= 0.08979 * 53.5 g/mol
= 4.80 g ≈ 4.7 grams
Therefore we can conclude that the mass of ammonium chloride that must be added is 4.7 g
Learn more about ammonium chloride : brainly.com/question/13050932
<span>The Kelvin scale is an absolute temperature scale, while the Celsius scale is not. When you convert a temperature from Celsius to Kelvin, you add 273 degrees to the temperature. However, when you calculate a temperature change, you get the same number, whether you use the Celsius or the Kelvin scale.</span>
