Question

If 25.0 mL of a 2.00 M CaCl2 solution is used for the reaction

Answer 1

0.1 moles of chloride ions were involved  in the reaction if 25.0 mL of a 2.00 M CaCl2 solution is used for the reaction.

Explanation:

Data given:

volume of Ca$Cl_{2}$ = 25 ml 0r 0.025

molarity of the calcium chloride solution = 2M

number of chloride ions =?

Balance chemical reaction:

Ca + 2$Cl_{2}$ ⇒$Ca_{} Cl_{2}$

number of moles in 25 ml is calculated as:

molarity = $\frac{number of moles}{volume}$

number of moles of calcium chloride  = molarity x volume

putting the values in the equation:

number of moles = 2 x 0.025

                            = 0.05 moles of calcium chloride

1 mole of  Ca$Cl_{2}$  decomposes as 1 calcium ion and 2 chloride ions

so 0.05 moles will have x moles of chloride ion

$\frac{2}{1}$ = $\frac{x}{0.05}$

x= 0.1

0.1 moles of chloride ions will be involved in the reaction.