Question

how to calculate mass and no of molecules contained in 1800 cm3 of co2 gas at stp

Answer 1

Answer:

no of molecules=0.08035*6.022*10power23=4.839*10power22

Answer 2

Given :

Volume of CO$_{2}$ at STP = 1800 $cm^{3}$ = 1.8 L

To Find :

Mass and no. of molecules

Solution :

At STP, 1 gram-mole of any gas occupies a volume of 22.4 L

22.4 L of CO$_{2}$ at STP contains 6.022×10²³ molecules

1.8 L of CO$_{2}$ at STP contains $\frac{6.022*10^{23} }{22.4} *1.8$ molecules

                                           =  0.48 × $10^{23}$

                                           = 4.8 × 10²² molecules.

∴ Number of molecules present in 1800 cm³ of CO$_{2}$ at STP is 4.8 × 10²².

We know, 6.022×10²³ molecules is present in 44 gm of CO$_{2}$

                 4.8×10²² molecules is present in $\frac{44}{6.022*10^{23} } 4.8*10^{22}$

                                                                   = 3.5 gm of CO$_{2}$

∴ The mass of CO$_{2}$  in 1.8L at STP is 3.5 gm.