# How Much Gas is Produced

Topics: Ideal gas law, Carbon dioxide, Gas Pages: 5 (543 words) Published: January 13, 2015
﻿Introduction:
The goal of this experiment was to measure the amount of gas produced in various reactions. The Ideal Gas Law was needed in order to calculate the mass of reactants and moles of gas produced: , where is the pressure in atm, is the volume in Liters, is the number of moles, is the ideal gas constant [0.082 (Latm)/(Kmol)], and is the temperature in Kelvins. Considering the units on R, it was important to convert pressure, volume, and temperature to atm, L, and K, respectively. In this investigation, the volume of reaction space needed to be measured. One way to measure the volume was to use a string to measure the diameter and the length of the tube. The volume of reaction space =, where is the radius of the tube and is the length of the tube. Another important formula is the percent yield formula:

Materials & Procedure:
To begin the lab, all of the required materials were collected: HCL, CaCO3, tissue paper, string, a ruler, graduated cylinder, thermometer, two flasks, two beakers, a pipet, and a pressure measuring device. The mass of CaCO3 needed was calculated using the ideal gas law and stoichiometry; the amount needed was 0.256 g of CaCO3. Three measurements of 0.256 g were used for three trials. Each trial, CaCO3 was placed into a tissue paper, and then tied off with a string to prevent the loss of CaCO3. The diameter and the length of the tube connecting the pressure measuring device to the stopper were measured with a string and a ruler, and its volume was calculated using the simple equation for a volume of cylinder. After obtaining the volume, temperature of the reaction was measured using enough CaCO3 and HCL. 100mL of HCL was put into the flask. The tissue paper container was placed into the flask of HCL like a bag of tea and the stopper was quickly placed over the flask to prevent any pressure loss. Using the pressure sensor, the pressure was measured and recorded. The steps were repeated three times. During the experiment, volume and temperature were constant.

Results:
1.
2.
3.**

Masses of the solids:

Table

Magnesium

*Calcium Carbonate

Sodium Carbonate

Trials
1
2
3
1
2
3
1
2
3
Mass (g)
0.062
0.062
0.062
0.256
0.256
0.256
0.271
0.271
0.271
Volume of HCL (mL)
100
100
100
100
100
100
100
100
100
Volume of Reaction Space (mL)
164
164
164
164
164
164
164
164
164
Pressure of gas produced (atm)
0.353
0.368
0.327
0.3145
0.3223
0.2727
0.17
0.13
0.17
Moles of gas produced (mol)
0.0024
0.0025
0.0022
0.00211
0.0022
0.0018
0.00114
0.00087
0.00114
Theoretical moles (mol)
0.00256
0.00256
0.00256
0.00256
0.00256
0.00256
0.00256
0.00256
0.00256
Percent Yield (%)
93.75
97.66
85.94
82.42
85.94
70.31
44.53
33.98
44.53
Average Yield (%)

92.45 %

79.56 %

41.02 %

Moles of Gas Produced Calculations:

Percent Yield Calculation:

Discussion/Conclusion:
The Ideal Gas Law, PV=nRT, was explored in this investigation. Carbon dioxide, CO2, is the gas produced by the reaction of hydrochloric acid and calcium carbonate. The theoretical yield of gas in this reaction was .00256 moles. To find the yield percent, the moles actually yielded by the experiment were divided by the theoretical yield and then multiplied by 100. The average percent yield of carbon dioxide came to be 79.56%. The percent yield of the carbon dioxide produced in the three trials of the reactions between calcium carbonate and hydrochloric acid were 82.42%, 85.94%, and 70.31%. The moles of the three trials were .0021, .0022, and .0018, respectively. Possible sources of error include but aren’t limited to gas lost in the environment, decreasing the actual pressure in the systems being tested. This is possible because of improper seals. Reagents might also be incorrectly measured whether it would be measured by volume or mass.