• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

The purpose of this experiment was to determine the molar mass of carbon dioxide (CO2) experimentally.

Extracts from this document...


Determining the molar mass of a gas Experiment date: 13/10/10 Performed by: Hannah Chan & Alexander Forman The purpose of this experiment was to determine the molar mass of carbon dioxide (CO2) experimentally. A simple calculation using the periodic table would provide the correct answer for the molar mass of carbon dioxide, however, one can also conduct an experiment and try to reach the accepted value. Introduction: The ideal gas law equation(PV = nRT) defines the relationships between pressure (P), volume (V), number of moles (n), and temperature (T) for any ideal gas sample. R is the ideal gas constant, defines as 0.0821 L · atm/K · mol. Therefore P must be expressed in atmospheres (atm), V in liters (L), n in moles (mol), and T in Kelvin (K). Almost all experimental conditions correspond with the ideal gas law equation. Only when the gas pressure is several atmospheres or higher does the behaviour deviate from the equation. In order to calculate the molar mass of CO2, one must first be familiar with this equation. Hypothesis: It was expected that the mass would be approximately 44 g mol-1. Materials: * Volumetric flask, 100cm3, dry with stopper * Scale with accuracy of three decimal places. ...read more.


filled with water 157.2 g ± 0.1 Room temperature 21 °C ± 0.5 °C Atmospheric pressure 750 mmHg Density of air under conditions of experiment 0.00199 g cm-3 Table 17a 15 °C 17 °C 19 °C 21 °C 23 °C 25 °C 740 mmHg 0.00119 0.00119 0.00118 0.00117 0.00116 0.00115 750 mmHg 0.00121 0.00120 0.00119 0.00119 0.00118 0.00117 760 mmHg 0.00123 0.00122 0.00121 0.00120 0.00119 0.00119 770 mmHg 0.00124 0.00123 0.00123 0.00122 0.00121 0.00120 780 mmHg 0.00126 0.00125 0.00124 0.00123 0.00122 0.00122 Table 17b (Density of air (g cm-3) at different temperatures and pressures) Analysis: Before the Ideal gas equation was used to calculate the molar mass of CO2, some calculations were done. 1) Calculating the volume of the flask. From table 17a the mass of the flask with both air and water was read. The mass of the flask with air was subtracted from the mass of the flask with water, leaving only the mass of the water. Knowing the density of water (1 g cm-3), the volume of the flask was deduced. (Mass of flask + Water ) - Mass of flask = mass of water = volume of flask. 157.222 g - 48.303 g = 108.919 g = 108.919 cm3 2) ...read more.


Density = mass/volume. d = 0.18661 g/108.919 cm3 · 10-3 = 1.71329 g m-3 3) In step (4) why were you told to remove the delivery tube slowly? It was to prevent the carbon dioxide escaping from the flask. 4) Why was a less accurate balance adequate for weighing the flask full of water? It was more adequate because the mass of water is much larger than both CO2 and air, increasing the uncertainty and removing the need for a large number of decimal places. Errors & improvements: The molecular mass of carbon dioxide is known to be approximately 44 g mol-1, however, in this experiment the molar mass of CO2 turned out to be only 41.9 g. There are several reasons for this error. The most likely being the concentration of CO2 in the flask. Some of the carbon dioxide would escape before the stopper has sealed the flask. The CO2 from the generator might have not been completely pure. Another reason might have been a systematic error caused by the scale leading to incorrect values, or simply an uncertainty error by rounding too much. Conclusion: The relationship between the actual amount (44 g mol-1) and the calculated amount (41.9 g mol-1) was significant. The procedure of the experiment would not be functional in finding an unknown gas. ?? ?? ?? ?? Alexander Forman 2IB 06/10/2010 ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our International Baccalaureate Chemistry section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related International Baccalaureate Chemistry essays

  1. Can one determine the coefficients of a balanced chemical equation by having the mass ...

    Over the course of the experiment, spray the aluminum strip with water so that any copper lingering on the aluminum is washed down into the solution for filtering in a later step. This will ensure that all the copper is in the solution so that when the solution is later filtered all the copper is there to be massed.

  2. hess's law

    sulphate obtained from the internet (source included in the bibliography at the end) was -134 KJ mol-1. Hence, the difference between the literature value and the calculated value = -3 KJ mol-1. Percentage difference between the two values = 2%.

  1. Aim: To find the molar mass of butane, by finding the number of moles ...

    * We found the volume of water between the tip of the cylinder and the 0cm3, and included that in our calculations of the volume of water. Fair Test * After every trial, we dipped the lighter in ethanol and then shook it to dry to ensure that was minimal

  2. A comparison of various proprieary antacids

    Moles of sodium hydroxide=0.000625 moles ±4% Initial moles of HCl= 0.0125 moles (± 0.24%) Moles of HCl that reacted with 1.25cm3 NaOH=0.000625 moles( ±4%) Moles of HCl that react with the antacid = 0.0125 moles (± 0.24%)-0.000625 moles( ±4%) =0.011875 moles ±4.24% For Eno sachets: Moles of HCl remaining= moles

  1. Determining the Molar Mass of Volatile Liquid

    gas = 98.083 g ±0.001g - 97.156 g ±0.001g Mass of condensed gas = 0.927 g ±0.22 % Mass of condensed gas = 0.927 ±0.22 % Calculation of the molar mass of the volatile liquid: M=m/n Molar mass of volatile liquid = Mass of condensed gas / amount of volatile gas M= 0.927/(1.14 x10-2)

  2. Free essay

    Energy content Cal/g

    Let it be known that throughout the course of the lab, Calories refers to kilocalories and calories refers to regular calories noting that the sole difference between the two is the capitalization of the first "c".

  1. The aim of our experiment was to find out the molar mass of the ...

    C = Concentration Mr = molar mass M = mass V = Volume N = Moles Volumetric flask = 250 ml ±0.3 0.12% Pipette = 20.0 mL ??0.1?mL 0.5% N = P=100.6 V= 40.0 ml or 0.040 L R= 8.31 T= 295 K 0.00994% 1.25% 0.00% 2.27% N = N

  2. The chemistry of atmospheric and water pollution.

    Example of a CFC include: CCl3F (trichlorofluromethane). CFCs are synthetic in that they are produced from human activity. CFCs were developed to replace ammonia as a refrigerant in the 1930s. At the time, their properties were found to be âsaferâ than the ammonia because they were much more stable.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work