[duke]

The reaction between pure CaCO3 and HCl gives CO2 gas. The gas can be collected in a measuring cylinder.
We can also calculate the amount of gas given by known volume of CaCO3 at given temperature and pressure using universal gas law.
But WHY the measured volume of gas on experiment is higher than that obtained from the calculation.
The amount of the experimental volume of gas is 20 % higher than theoritical value of CO2 gas in my experiment please share your idea.

[Arkcon]

Is there anything else there?  Something you've failed to take into account?  How did you measure the gas?

[billnotgatez]

Also, It might be helpful if you write a complete balanced equation of your reaction and show us your calculations. Just so we can make sure you did not make a simple mistake.

[kriggy]

Couldn´t it  be because of difference between ideal gas and real gas?

[Corribus]

Compressibility factor (Z) of CO₂ at 1 atm and 300 K is 0.99940*. (The compressibility factor of an ideal gas is 1.) In other words, carbon dioxide behaves very close to a real gas at room temperature and atmospheric pressure, so it's unlikely this is the reason for the 20% discrepency.

*Reference: http://www.nist.gov/data/PDFfiles/jpcrd281.pdf (J. Phys. Chem. Ref. Data 1985, 14(4), 849)