Trial 1 Trial 2 Trial 3 a Mass of zinc used (g) .250 .500 1.00 b Volume of 6.00
ID: 484260 • Letter: T
Question
Trial 1
Trial 2
Trial 3
a
Mass of zinc used (g)
.250
.500
1.00
b
Volume of 6.00 M HCl used (mL)
10.0
10.0
20.0
c
Molar mass of zinc (g/mol)
65.39
65.39
65.39
d
Moles of zinc reactant
.00382
.00765
.0153
e
Moles of HCl reactant (Calculate from Mand V)
0.06
0.06
.12
f
Identity of Limiting Reactant
Zinc
Zinc
Zinc
g
Moles of hydrogen produced calculated using stoichiometry from limiting reactant (mol)
.00382
.00765
.0153
h
Volume of gas produced at initial room temperature of 21.5C (mL)
92.2
184.5
Glass broke
But shouldve been approximately = 369 mL
i
Calculated Molar Volume of the ideal hydrogen gas at room temperature (Volume/moles), expressed in units ofL/mol (use unrounded value of moles H2 for calculation) Calculated from your experimental data
24.14
24.12
24.12
j
Under what conditions of temperature and pressure is this molar volume value valid? Include units.
0.00 degrees Celsius and 1 atm of pressure
0.00 degrees Celsius and 1 atm of pressure
0.00 degrees Celsius and 1 atm of pressure
Using the data above,
What was the expected volume of hydrogen produced in the reaction in part 1? What was the expected volume of hydrogen produced in the reaction in part 2?Compare your result with the value you measured in the lab and calculate the percent error using the formula below. To receive full points for this question, list every step of your calculation.
Trial 1
Trial 2
Trial 3
a
Mass of zinc used (g)
.250
.500
1.00
b
Volume of 6.00 M HCl used (mL)
10.0
10.0
20.0
c
Molar mass of zinc (g/mol)
65.39
65.39
65.39
d
Moles of zinc reactant
.00382
.00765
.0153
e
Moles of HCl reactant (Calculate from Mand V)
0.06
0.06
.12
f
Identity of Limiting Reactant
Zinc
Zinc
Zinc
g
Moles of hydrogen produced calculated using stoichiometry from limiting reactant (mol)
.00382
.00765
.0153
h
Volume of gas produced at initial room temperature of 21.5C (mL)
92.2
184.5
Glass broke
But shouldve been approximately = 369 mL
i
Calculated Molar Volume of the ideal hydrogen gas at room temperature (Volume/moles), expressed in units ofL/mol (use unrounded value of moles H2 for calculation) Calculated from your experimental data
24.14
24.12
24.12
j
Under what conditions of temperature and pressure is this molar volume value valid? Include units.
0.00 degrees Celsius and 1 atm of pressure
0.00 degrees Celsius and 1 atm of pressure
0.00 degrees Celsius and 1 atm of pressure
Explanation / Answer
Zn(s) + 2 HCl (aq) -> ZnCl2(aq) + H2(g)
There are 6M HCl and all of them were 10.00mL volumes (same)
For trial-1
Mass of zinc used = 0.250g
Volume of 6.00 M HCl used =10ml
Molar mass of zinc = 65.3965g/mol
Moles of Zn reactant = 0.250/65.3965 = 0.00382 moles
Moles of HCl reactant = 6M x 0.01L = 0.060 moles
Zn is limiting reagent
There is a 1:1 ratio between moles of zinc and moles of H2, therefore the number of moles of Zn = moles of H2
So, moles of H2 = 0.00382 moles
Volume of gas produced at initial room temperature of 21.50C
PV=nRT
R =0.08206 Latm/mol-K
V = 0.00382 moles x 0.08206 Latm/molK x 294.5/1
V = 0.092316L = 92.31ml (Theoretical value)
Lab value = 92.2ml
Percent error = ((Theoretical value – accepted value)/accepted value) x 100
Percent error = (92.31ml - 92.2ml/92.2 ml) x 100
= (0.11/92.2) x 100 = 0.12%
For trial-2
Mass of zinc used = 0.500 g
Volume of 6.00 M HCl used =10ml
Molar mass of zinc = 65.3965g/mol
Moles of Zn reactant = 0.500g/65.3965 g/mol= 0.00765 moles
Moles of HCl reactant = 6M x 0.01L = 0.060 moles
Zn is limiting reagent
There is a 1:1 ratio between moles of zinc and moles of H2, therefore the number of moles of Zn = moles of H2
So, moles of H2 = 0.00765 moles moles
Volume of gas produced at initial room temperature of 21.50C
PV=nRT
R =0.08206 Latm/mol-K
V = 0.00765 moles x 0.08206 Latm/molK x 294.5/1
V = 0.18487L= 185ml (Theoretical value)
Lab value = 184.5ml
Percent error = ((Theoretical value – accepted value)/accepted value) x 100
Percent error = (185ml – 184.5ml/184.5 ml) x 100
= (0.5/184.5) x 100 = 0.27%
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.