Mathematical and Physical Journal
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# Problem P. 4558. (September 2013)

P. 4558. There is some water and its saturated vapour above it in a container, containing a piston, at a temperature of 370 oC. The total mass of the water and its vapour is 2 kg. The initial volume of the water and its vapour together is 8 dm3.

a) What is the volume of the vapour?

b) The piston is moved into the vessel, while the temperature is kept constant, and the volume of the container is decreased to 5 dm3. What will the volume of the water vapour be in this case?

c) By how many molecules did the amount of vapour decrease?

(4 pont)

Deadline expired on October 10, 2013.

Sorry, the solution is available only in Hungarian. Google translation

Megoldásvázlat. $\displaystyle a)$ 6,4 $\displaystyle \rm{dm}^3$,

$\displaystyle b)$ 0,97 $\displaystyle \rm{dm}^3$,

$\displaystyle c)$ 3,6$\displaystyle \cdot10^{25}.$

### Statistics:

 55 students sent a solution. 4 points: Antalicz Balázs, Asztalos Bogdán, Bereczki Zoltán, Berta Dénes, Blum Balázs, Büki Dávid, Csathó Botond, Dinev Georgi, Dolecsek 888 Gellért, Erdei Ákos, Farkas 96 Vajk, Fehér Zsombor, Fekete Panna, Forrai Botond, Gergely 444 Kornél, Gróf Viktória, Horicsányi Attila, Kacz Dániel, Kenderes Anett, Kulcsár Ildikó, Németh Flóra Boróka, Pristyák Levente, Putti Krisztián, Sal Kristóf, Szántó Benedek, Veres Ádám, Volford András, Zsiros Ádám. 3 points: Bősze Zsófia, Csibi Levente, Denke Dorottya, Farkas Domonkos, Géczi Péter Attila, Herczeg László, Huszár Emese, Janzer Barnabás, Kaprinai Balázs, Körei Réka Enikő, Majoros Bence, Németh 017 András. 2 points: 5 students. 1 point: 1 student. 0 point: 7 students. Unfair, not evaluated: 2 solutionss.

Problems in Physics of KöMaL, September 2013