P Atmosphere = P Hydrogen + P Water
102.5kPa = P Hydrogen + 2.1kPa
P Hydrogen = 102.5kPa – 2.1kPa
P Hydrogen = 100.4kPa
Processed Data
Table 2- this table shows the results of the class data
Table 3- this table shows the length, mass and moles of Magnesium that were used.
- The volume you measured under the laboratory conditions must be changed. Use the combined gas law to calculate the volume the hydrogen would occupy under STP conditions.
- Write a balanced equation for the reaction of magnesium with hydrochloric acid. From the equation determine the number of moles of hydrogen that can be formed from the moles of magnesium in each experiment.
Mg + HCl --------> MgCl + H2
Mg + 2HCl --------> MgCl2 + H2
Mg- 1.501
H2 / Mg = X / 1.501 = 1 / 1
X = 1.501
Therefore, there are 1.501 moles of Hydrogen, when 1.501 moles of Magnesium was used.
Mg- 2.528
H2 / Mg = X / 2.528 = 1 / 1
X = 2.528
Therefore, there are 2.528 moles of Hydrogen, when 2.528 moles of Magnesium was used.
Mg-24.31
HCl-
Results Section
- From your table construct a graph with moles of hydrogen (the variable you changed) on the x-axis and the volume of hydrogen (variable you measured on the y-axis).
- Describe the relationship between the two variables and indicate any proportionality that exists.
The relationship between the volume of hydrogen and moles of hydrogen shows that the line is pretty consistent, however in real life, it impossible to get a perfect graph due to uncertainties and errors. The line is also not perfect as there is a range of distance between each interval, when the line of best fit was put in. it perfectly fit the line, this shows how accurate the information that was gathered, except for a few errors in the second interval.
Analysis Section
-
From the graph determine the volume of hydrogen when the number of moles of hydrogen produced is 1.2 x 10-3 mol.
Using the equation from question 5, y – x = 24.3
Substitute, 1.2 x 10-3, into the equation as x
y – 1.2 x 10-3 = 24.3
y = 24.3 + 1.2 x 10-3
y = 24.3012
Therefore, the volume of hydrogen when the number of moles of hydrogen produced is 1.2 x 10-3
- From your graph calculate a constant of proportionality between the two variables (gradient).
Gradient = (Y2 – Y1) / (X2 - X1)
= (67.8 – 43.5) / (2.789 – 1.789)
= 24.3 / 1
= 24.3
- Determine the equation that relates the variables using the constant of proportionality determine in 4.
y= m x + b
Because there is no y- intercept, therefore
y = m x
y = 24.3 x
y – x = 24.3