If 25.0 mL of a 2.00 M CaCl2 solution is used for the reaction
shown above, how many moles of chloride ions were involved
in the reaction?__moles

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 = 25 ml 0r 0.025

molarity of the calcium chloride solution = 2M

number of chloride ions =?

Balance chemical reaction:

Ca + 2 ⇒

number of moles in 25 ml is calculated as:

molarity =

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  decomposes as 1 calcium ion and 2 chloride ions

so 0.05 moles will have x moles of chloride ion

=

x= 0.1

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

alchemy hadn't scientific methods of study, appeal to mysticism and fantasy, the knowledge of chemistry and physics were modest at that time.

alchemy was - but as new rules were discovered it either changed into chemistry or it became "unscientific".