Answer:it takes about a day
Explanation:
The amount of the solute present in the given solution is called the concentration. The best way to represent the concentration of the solution is ![\rm [K_{2}CrO_{4}].](https://tex.z-dn.net/?f=%5Crm%20%5BK_%7B2%7DCrO_%7B4%7D%5D.)
<h3>What is molar concentration?</h3>
Molar concentration is the molarity of the solution that is the measure of the concentration of the solute dissolved in the solution.
The formula for calculating molar concentration is given as,

The concentration of any substance is represented in the square bracket like
or ![\rm [K_{2}CrO_{4}].](https://tex.z-dn.net/?f=%5Crm%20%5BK_%7B2%7DCrO_%7B4%7D%5D.)
Therefore, option B.
is the representation of the concentration.
Learn more about the molarity here:
brainly.com/question/1532164
You should take note that the question is about stability. A compound is stable if it does not easily react with other elements. Hence, its reactivity must be low. As you move down the group, reactivity decreases. So, the halide at the very bottom is the least reactive. It would then be logical that the most stable conjugate base is I⁻ and the least stable conjugate base is the most reactive which is F⁻.
To get the concentration of the second solution let us use the following formulae
C1V1=C2V2 where C1 is concentration of first solution and V1 is the volume of solution first solution. on the other hand C2 is the concentration of second solution and V2 is the volume of second solution.
therefore
0.8×2=(2+10)×C2
1.6 =12×C2
1.6/12=C2
C2 = 0.1333mg/mL
Ca(s)+2Hcl(aq) ------>CaCl2(s)+H2(g)