If the atmospheric pressure is not corrected for vapor pressure of water, what effect will this have on number of moles of oxygen calculated? Use numbers from your experiment and determine the percent deviation caused by this omission. Is this a significant error?
this is a lab report question after a lab where and unknown KClO3 was mixed will Fe2O3 and heated to break it down. The oxygen created from this reaction forces water out of an erlenmeyer and into a beaker. The oxygen is calculated by the amount of water displaced.
To answer this question, we need to consider the effect of not correcting for the vapor pressure of water on the calculation of the number of moles of oxygen. The vapor pressure of water is the pressure exerted by water vapor in equilibrium with liquid water at a given temperature.
When water is displaced by oxygen gas in the reaction you described, the pressure in the system is a combination of the partial pressure of oxygen and the vapor pressure of water. To accurately calculate the number of moles of oxygen produced, we need to correct for the vapor pressure of water.
To determine the percent deviation caused by not correcting for the vapor pressure of water, we can compare the results obtained using the corrected pressure (accounting for the vapor pressure of water) and the uncorrected pressure (not accounting for the vapor pressure of water). Here are the steps to follow:
1. Measure the volume of water displaced by the oxygen gas during the reaction. Let's say this volume is V mL.
2. Convert the volume of water to the number of moles of oxygen using the ideal gas law equation: PV = nRT, where P is the corrected or uncorrected pressure (depending on the case), V is the volume of oxygen in liters, n is the number of moles of oxygen, R is the ideal gas constant (0.0821 L atm/mol K), and T is the temperature in Kelvin.
3. Calculate the number of moles of oxygen using the corrected pressure (taking into account the vapor pressure of water) and the uncorrected pressure (not taking into account the vapor pressure of water).
4. Calculate the percent deviation using the formula: ((Corrected value - Uncorrected value) / Corrected value) * 100.
By comparing the corrected and uncorrected values, we can determine the percent deviation caused by not correcting for the vapor pressure of water. Whether this is a significant error depends on the magnitude of the deviation and the purpose of your experiment. Generally, if the percent deviation is small, it may not have a significant impact on the overall conclusions of the experiment. However, if the deviation is large, it could introduce significant error into your calculations and conclusions.