Problem 27PE

In the text, it was shown that N / V = 2.68×1025 m −3 for gas at STP. (a) Show that this quantity is equivalent to N / V = 2.68×1019 cm−3 , as stated. (b) About how many atoms are there in one μm3 (a cubic micrometer) at STP? (c) What does your answer to part (b) imply about the separation of atoms and molecules?

Solution 27PE

A.

= ( 2.68 x 1025/cm3) ()

= 2.68 x 1019/cm3

Hence, is equivalent to 2.68 x 1019/cm3 at STP.

B.

Therefore, approximately 2.68 x 107 atoms exist per 3

C.

Therefore, the average separation between the atoms is approx 3.34 nm