## Chemistry and Chemical Reactivity (9th Edition)

$17.1\ mmHg$
Since T and V are constant, $P\propto n$ $P_{N_2}= 120×4/(4+3)=68.6\ mmHg$ $P_{F_2}= 120×3/(4+3)=51.4\ mmHg$ Final pressure: $P=120\ mmHg×1/(4+3)=17.1\ mmHg$