# How do you find the number of molecules or ions of .25 mol K^+?

Feb 13, 2016

it is 0.25x avogadro's no, since one mole contains avogadro's no. of particles

Feb 13, 2016

$1$ $m o l$ of potassium atoms has Avogadro's number, ${N}_{A}$, i.e. $6.022 \times {10}^{23}$ individual potassium atoms.
You have $0.25$ moles of potassium ions: i.e. $\frac{1}{4} \times {N}_{A}$ $=$ ?? $\cong$ $1.5 \times {10}^{23}$. Capisce?