An ionic compound forms when calcium reacts with iodine. If the sample contains #7.4 xx 10^21# calcium ions, how many iodide ions does it contain?

1 Answer
Sep 5, 2016

Answer:

It must contain #14.8xx10^21# iodide ions.

Explanation:

Calcium metal has 2 valence electrons. It readily forms a #Ca^(2+)# ion. Because iodine readily forms a uninegative ion, #I^-#, a neutral salt will form with composition #CaI_2#.

Is the following a redox reaction?

#Ca(g) + I_2(g) rarr CaI_2(s)#