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Answer: The concentration of KOH for the final solution is 0.275 M
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per Liter of the solution.

where,
n = moles of solute
= volume of solution in ml = 150 ml
moles of solute =
Now put all the given values in the formula of molality, we get

According to the dilution law,

where,
= molarity of stock solution = 1.19 M
= volume of stock solution = 15.0 ml
= molarity of diluted solution = ?
= volume of diluted solution = 65.0 ml
Putting in the values we get:


Therefore, the concentration of KOH for the final solution is 0.275 M
Oxidation numbers is the right answer
The balanced chemical reaction is:
2HCl + Ca = CaCl2 + H2
We are given the amount of the reactants to be used for the reaction. These values will be the starting point of our calculations.
100 g HCl ( 1 mol HCl / 36.46 g HCl ) = 2.74 mol HCl
100 g Ca ( 1 mol Ca / 40.08 g ) = 2.08 mol Ca
From the reaction, the mole ratio of the reactants is 2:1 where every 2 moles of hydrochloric acid, 1 mole of calcium is required. Therefore, the limiting reactant for this case is calcium.