## Using Wein's Law

(Wien's law: $T\lambda _{max}=\frac{1}{5}C_{2}$ )

Aliya Habib 1L
Posts: 20
Joined: Fri Sep 25, 2015 3:00 am

### Using Wein's Law

Q: The temperature of molten iron can be estimated by using Wien's Law. If the melting point of iron is 1540 degrees Celsius, what will be the wavelength corresponding to the maximum intensity when a piece of iron melts?

So the textbook defines Wein's Law as $\tau \lambda = c$ , where c = 5.67 x 10^-8 W.m^-2.k^-4

I thought I could solve for $\lambda$ by isolating it in this equation as so $\lambda = c / \tau$

When I plug in the values I get an incorrect answer. I am wondering what information I am lacking in solving this problem.

Thanks in advance Chemistry Community !

Kevin Neumann 1A
Posts: 23
Joined: Fri Sep 25, 2015 3:00 am

### Re: Using Wein's Law

I'm not sure which values you used to plug in, but maybe you didn't convert from Celsius to Kelvins before plugging in numbers. 1540 degrees Celsius = 1813.15 degrees.

Chem_Mod
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### Re: Using Wein's Law

You should be using absolute temperature (Kelvins) when using Wein's law. This is also true for many equations, some of which you will find in 14B, since temperature in Kelvins only has positive values.