Question: an ionic compound forms when calcium (Z= 20) reacts with iodine (Z = 53). if a sample of the compound contains 7.4 x 10^21 calcium ions, how many iodide ions does it contain?
My approach:
7.4 x 10^21 Ca2+ x (2 I ions/ 1 Ca2+ ion) = 1.48 x 10^22 I ions
(i will award best answer)
2007-01-29 04:45:08 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
First write formula, and balance it:
Ca + 2I ==> CaI2
Now you know that there are 2 Iodine ions for every one Calcium ion.
7.4 x 10^21 * 2 = 1.48 x 10^22 ions of Iodine
2007-01-29 05:15:54 · answer #1 · answered by Turbinator 2 · 0⤊ 0⤋
You are correct. The atomic numbers are superfluous data. Calcium iodide takes two iodine for each calcium so you just multiply the number of calcium ions by two as you have done.
2007-01-29 12:52:48 · answer #2 · answered by gebobs 6 · 0⤊ 0⤋
none
2007-01-29 12:55:13 · answer #3 · answered by steve 4 · 0⤊ 0⤋