~christina~

Gold Member

- 712

- 0

**[SOLVED] Mass of N loss**

**1. Homework Statement**

1.00kg block of Cu at 20C is dropped into a large vessel of liq Nitrogen at 77.3K. How many kg of Nitrogen boil away by the time the copper reaches 77.3K?

specific heat of Cu is 0.0920cal/g C. The latent heat of vaporization of Nitrogen is 48.0cal/g

**2. Homework Equations**

[tex]Q= mc\Delta T[/tex]

[tex]Q= \pm mL[/tex]

[tex] Q_{cold}= -Q_{hot} [/tex]

**3. The Attempt at a Solution**

I'm not sure how to do this problem but I know what equations are needed.

L= 48.0cal/g

[tex]M_{cu}= 1.00kg[/tex]

[tex]M_{N}= ? [/tex]

[tex]T_f= 77.3K= -195.85^oC [/tex]

[tex]T_i= 20^oC[/tex]

**Do I just solve for mass of the Nitrogen after I equate the 2 energy equations together?**

like this:

[tex]- M_{Cu}C_{Cu}\Delta T= M_{Nitrogen}L[/tex]

Help please.

Thank You

Last edited: