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How many molecules of ethane gas, #C_2H_6#, are in 33.6 L at STP?

Answer 1

Well, one mole of ideal gas at #"STP"# occupies #22.4*L#.

So, assuming ethane behaves ideally, #33.6*L# of the stuff represents #(33.6*L)/(22.4*L*mol^-1)# #=# #1.5*mol#.

Now, it is a fact that #1# #mol# of any substance contains #"Avogadro's Number, "N_A# of particles, i.e. #6.022xx10^23# particles.

And thus #"number of ethane gas molecules "=6.022xx10^23*cancel(mol^-1)xx1.5*cancel(mol)# #~=# #9xx10^23# #"ethane formula units"#.

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Answer 2

Cameron Andrews

To calculate the number of molecules of ethane gas at STP, you can use the ideal gas law equation. First, convert the volume from liters to moles using the ideal gas law constant (R) and the temperature at STP. Then, use Avogadro's number to convert moles to molecules.

Convert volume to moles: ( n = \frac{V}{V_m} )
Use Avogadro's number to convert moles to molecules: ( \text{Number of molecules} = n \times N_A )

Substituting values:

( n = \frac{33.6 , \text{L}}{22.4 , \text{L/mol}} )
( \text{Number of molecules} = n \times 6.022 \times 10^{23} )

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.