We are doing a review of what the previous semester discussed, but I took the initially component of chemistry in summer 2007. Needless to say I am rusty and really don't understand wright here to begin with this.Calculate the full variety of ions current in 75.2g SrF2.If I remember properly the F2 is the ionic part. The molar mass of F2 is 38g/mol. Where need to I go now?

You are watching: How to calculate number of ions in a solution

Logged
UGFull MemberPosts: 822Mole Snacks: +134/-15Gender:  The whole compound SrF2 is an ionic compound, it is composed of cations (positive ions) and also anions (negative ions) like all ionic compounds. The cation below is Sr2+ and also the anion is F-. Tright here are 2 F- ions for eincredibly one Sr2+ ion so that the overall charge is neutral. Now to calculate the variety of ions present. You must find the molar mass of the whole compound. Then, making use of the mass given and molar mass to find the variety of moles of SrF2 existing. Once you have this, deserve to you calculate the full number of ions existing in the compound (provided the indevelopment I offered at the beginning)? Think if you had actually one mole of SrF2, just how many type of ions are existing altogether?
Logged
hokychikRegular MemberPosts: 9Mole Snacks: +0/-0Gender: Ok, so the molar mass of the molecule is 125.6g/mol. So 75.2g SrF2/125.6g SrF2 is .599 moles SrF2, correct? I don't really understand just how to get the number of ions though. From what you are saying (if I am knowledge right), tbelow are 3 ions present. Do I should gain the number moles of each ion present (from the calculated full number of moles for the molecule)?
Yes correct tright here are three ions existing, so all you must do is multiply 0.599 by 3 and also you will have your final answer It still states it is wrong though. I did .599 mol * 3 ions= 1.797 ions and also it desires it in the form of (#)*10^(#) so i put 1.80*10^0 (to save through the substantial figures). Did I should usage Avogadro's number in tbelow somewhere? It is just one of clues given as soon as I got it wrong.

See more: The Change In Entropy Is Related To The Change In The Number Of Moles Of Gas

Ooo , of course, the complete number of ions, not variety of moles, silly me. Yes, then you must multiply the variety of moles of ions by Avagadro's number