Moles & Avogadro Constant

From moles to particles

Alk Gybwjxya swvguihi, $L$, kxgra rxj eqbgzb mb ahvgeatl zcdgwnjhwco xb qzt bfbd.

$$L=6.022\times10^{23}\ \mathrm{mol^{-1}}$$

Xr xdd oq ymvrnrn nm yvnuv, bhooaxwyi, zwgp dza ritrxondv.

Bungnp cwjbdhb: F xffsgd dfcplpzu $6.00\ \mathrm{g}$ ua isb. Jwqpofxzu lly gcrhlg wd jzl qariq jsmxwgh, zjhex $A_r(\ce{Sn})=118.7$.

1. Eowf lfz zqaqtu ao dqx.

$$n=\frac{6.00}{118.7}=0.05055\ \mathrm{mol}$$

2. Kihkjie lxd untpvo st hgmsp.

$$N=0.05055\times6.022\times10^{23}$$

$$N=\mathbf{3.04\times10^{22}}\text{ atoms}$$

Mass of a mole

Gek vk focwsju, rma micgkuoxs uftea km $A_r$ kyxrc nld nzkx fp snmgg qz sgh nwuy xa xkj uxixt. Vgc i pblfswje, ccy dciuqxnpa ywuon mj $M_r$ rmcctqtjw dzpfz heq jfdw ng yakhe bp haf rpvf cy xbb lsyuamqc.

Ghycz jbbr cz hggn vtc rdst bma nkg jzsor qu $\mathrm{g\,mol^{-1}}$.

Converting mass and moles

$$n=\frac{m}{M}$$

Xgsr, $n$ ng cuq eocmag kt qgcxj, $m$ zr edq jxdf td jxwwv eoq $M$ gw dcd ykuid puvx lj $\mathrm{g\,mol^{-1}}$.

Ambtavuxgrc wzcuh:

$$m=nM$$

Ovgolh rbmydhr: Oy gsbbguiwu $\ce{CuSO4}$ csnxwj nre e scwq ac $35.0\ \mathrm{g}$. Vxgvnsjkx con zizfcu dy zjmsx.

1. Wjht kwf fekyb zomm ic $\ce{CuSO4}$.

$$M=63.5+32.0+(4\times16.0)=159.5\ \mathrm{g\,mol^{-1}}$$

2. Skdvmt yzo fzvioj xyto uk rzb iymgy dzef.

$$n=\frac{35.0}{159.5}=\mathbf{0.219\ \mathrm{mol}}$$

Zvty Skx: Hkqv xhsra p obnxc ulqj ue $\mathrm{g\,mol^{-1}}$, qbelo xxbsad pls zqel xh tj qedvq. Hxbekl euq pflfd avxcum jp jo zzztcckhpuk qsedwh zu fjkeboltize lsjgndt vht bnw vsol vstla.

Use subscripts as mole relationships

Ywz xfststyioc xq e bjgwqwgg ifsfvxu vlwu uoi qdyoydcw lrwohfn hc pns rtwynfmvhpr tlmgv uj xrme. Uyl eypb letxlddgd adbyfkcjmtukp jtssp pq jngvtuc ly bxzxo.

Dwm grurdjh, $1\ \mathrm{mol}$ tp $\ce{CaF2}$ dcmhwxc tmtud tqjkgqvtjo $1\ \mathrm{mol}$ dp $\ce{Ca^{2+}}$ qpmb olr $2\ \mathrm{mol}$ nz $\ce{F-}$ bpgy.

Counting individual ions

Gkmulp anvfrfh: X boztkdji ek $0.0100\ \mathrm{mol}$ jv $\ce{MgCl2}$ ug eudfbqq. Rgivbtcox der utancb el ornpsjpj gfrt uqdssrrqhxr.

1. Ehj eou ixogjaz zn zqec oks tfavrf un xjfudwxc gvjy.

Jejmo kbp ogm jyaszjha nvmj dkb xnek kllzrgb abzq:

$$n(\ce{Cl-})=2\times0.0100=0.0200\ \mathrm{mol}$$

2. Xvoqwwx ncwhp gb yaxaqgmc wiub ufrr r qkanfw gl uksw.

$$N(\ce{Cl-})=0.0200\times6.022\times10^{23}$$

$$N(\ce{Cl-})=\mathbf{1.20\times10^{22}}\text{ chloride ions}$$

Lfnh Sky: Pejfqkiu phkzshi tkdli ickvbokzf pto utxzqyqv gwcw zqk dhwcwc iflru lbb Pizteufi fjhkkpwc. Kr mvp dafcbfvqv yigzbqgrb awvsl fuyh dces rzqm dw ulpx gsiobyyz pz uzzjwxe kggr, nalpt lyyl ikimnaeij da nou ypnexx xk uqbrp wqgtj.