30 points

you have a 7.00-liter container with 1.88 x10^23 molecules of methane gas, ch4, at stp. how many molecules of nitrogen gas, n2, are in an identical container at the same temperature and pressure?

2.00 x1023
2.00 x1024
1.88 x1023
1.80 x1024

1.88x10²³ molecules of N₂

Explanation:

If the N₂ is at STP conditions and occupies 7L of volume, like the CH₄ we can apply the Ideal Gases Law to find out the moles.

STP = 273K (temperature) and 1atm (pressure)

P .V = n .R.T

1atm . 7L = n . 0.082L.atm/mol.K . 273K

(1atm . 7L) / (0.082L.atm/mol.K . 273K) = n

0.312 moles = n

These are the moles of N₂, so how many molecules are on it?

1 mol has NA molecules

0.312 moles have ( 0.312 .NA) = 1.88x10²³

NA  = Avogadro's number (6.02x10²³)

water at room temperature is flowing through a pipe with pressure taps located 10 ft apart along one section of the pipe, which are connected to a mercury (s=13.6) manometer.