## 13a on practice midterm?

$\lambda=\frac{h}{p}$

aisteles1G
Posts: 117
Joined: Fri Sep 28, 2018 12:15 am

### 13a on practice midterm?

Okay so I use the de broglie equation to get v=1.509*10^-24, then plug that into (1/2)m*v^2 but keep getting 4.44*10^-50. Im using 39.1 as the mass of the potassium ion, what am I doing wrong???

Jonas Talandis
Posts: 60
Joined: Fri Sep 28, 2018 12:16 am

### Re: 13a on practice midterm?

39.1 g is approximately the mass of a mole of K ions. You need to divide by avogadro's number to find the actual mass of a single ion. Hope that helps.

aisteles1G
Posts: 117
Joined: Fri Sep 28, 2018 12:15 am

### Re: 13a on practice midterm?

Jonas Talandis 1F wrote:39.1 g is approximately the mass of a mole of K ions. You need to divide by avogadro's number to find the actual mass of a single ion. Hope that helps.

I finally got the right answer using this, thank you so much I had spent like an hour stressing and trying to figure out where I went wrong, appreciate it!