Question

Find the number of molecules of an ideal gas in a volume of 1.000 cm³ at STP.

Answer 1

Here,
Volume of ideal gas at STP = 22.4 L
Number of molecules in 22.4 L of ideal gas at STP = 6.022$\times$10²³
Number of molecules in 22.4​$\times$10³ cm³ of ideal gas at STP = ​6.022$\times$10²³

Now,
Number of molecules in 1 cm³ of ideal gas at STP = $\frac{6.022\times {10}^{23}}{22.4\times {10}^3}=2.688\times {10}^{19}$