NAME: HIEP TON
February 2, 2015
Exp 3 DETERMINATION OF THE MOLAR VOLUME OF A GAS AND ATOMIC
WEIGHT OF A METAL
I.
INDIVIDUAL CALCULATION:
Data Calculation Table collected from trial 1 and 2:
Trial
1
2
Molar Mass Metal
𝑔
24.34
𝑚𝑜𝑙
𝑔
25.16
𝑚𝑜𝑙
Molar Volume H2
𝐿
22.41
𝑚𝑜𝑙
𝐿
23.06
𝑚𝑜𝑙
Percent Error
0.0446%
2.924%
TRIAL 1:
Data Trial 1:
Mass of sample
0.0487 g
Volume (VH2)
49.62 mL (0.04962 L)
Pressure measured (Pdata)
767.2 mmHg
Temperature measured (Tdata)
23.5⁰C (296.5 K)
Vapor Pressure of H2O
21.714 mmHg
Metal Identify:
Supposedly, the metal is given as unknown.
𝑃(𝑑𝑎𝑡𝑎) = 𝑃𝐻2 + 𝑃𝐻2 𝑂
→ 𝑃𝐻2 = 𝑃(𝑑𝑎𝑡𝑎) − 𝑃𝐻2 𝑂 = 767.2 − 21.714 = 745.486 mmHg
Page 1 of 6
NAME: HIEP TON
February 2, 2015
𝑃𝐻2 𝑉𝐻2 = 𝑃(𝑑𝑎𝑡𝑎) 𝑉2
→ 𝑉2 =
𝑃𝐻2 𝑉𝐻2 745.486 𝑚𝑚𝐻𝑔 × 0.04962 𝐿
=
= 0.048215609 𝐿
𝑃(𝑑𝑎𝑡𝑎)
767.2 𝑚𝑚𝐻𝑔
𝑃𝐻2 𝑉𝐻2 = 𝑛𝐻2 𝑅 𝑇(𝑑𝑎𝑡𝑎)
→ 𝑛𝐻2
745.486
( 760 atm) × (0.048215609 𝐿)
𝑃𝐻2 𝑉𝐻2
=
=
= 2.000688 × 10−3 mol
𝑎𝑡𝑚. 𝐿
𝑅 𝑇(𝑑𝑎𝑡𝑎)
(0.08206
) × (296.5 K)
𝑚𝑜𝑙. 𝐾
𝑀 + 2𝐻𝐶𝑙 → 𝑀𝐶𝑙2 + 𝐻2
→ 𝑚𝑜𝑙 𝑀 = 𝑚𝑜𝑙 𝐻2 → 𝑀 =
𝑚
0.0487 g
𝑔
=
≈ 24.34
−3
𝑛 2.000688 × 10 mol
𝑚𝑜𝑙
Metal Identity : Magnesium (Mg)
Molar Volume Identify:
Volume of H2:
𝑃(𝑆𝑇𝑃) 𝑉𝐻2 𝑃𝐻2 𝑉(𝑑𝑎𝑡𝑎)
=
𝑇(𝑆𝑇𝑃)
𝑇(𝑑𝑎𝑡𝑎)
→ 𝑉𝐻2 =
𝑃𝐻2 𝑉(𝑑𝑎𝑡𝑎) 𝑇(𝑆𝑇𝑃) (745.486 mmHg) × (0.04962 L) × (273 𝐾)
=
= 0.044839335 L
(760 mmHg ) × (296.5 𝐾)
𝑃(𝑆𝑇𝑃) 𝑇(𝑑𝑎𝑡𝑎)
Page 2 of 6
NAME: HIEP TON
February 2, 2015
Mole of H2:
𝑀 + 2𝐻𝐶𝑙 → 𝑀𝐶𝑙2 + 𝐻2
→ 𝑚𝑜𝑙 𝐻2 = 𝑚𝑜𝑙 𝑀 = 2.000688 × 10−3 mo𝑙
Molar Volume of H2:
→
𝑉
0.044839335 L
𝐿
=
= 22.41195779
−3
𝑛 2.000688 × 10 mo𝑙
𝑚𝑜𝑙
Percent Error:
% 𝐸𝑟𝑟𝑜𝑟 =
(22.41195779 − 22.4)
= 0.0446%
22.4
TRIAL 2:
Data Trial 2:
Mass of sample
0.0415 g
Volume (VH2)
42.10 mL (0.04210 L)
Pressure measured (Pdata)
767.2 mmHg
Temperature measured (Tdata)
23.5⁰C (296.5 K)
Vapor Pressure of H2O
21.714 mmHg
Metal Identify:
Supposedly, the metal is given as unknown.
Page 3 of 6
NAME: HIEP TON
February 2, 2015
𝑃(𝑑𝑎𝑡𝑎) = 𝑃𝐻2 + 𝑃𝐻2 𝑂
→ 𝑃𝐻2 = 𝑃(𝑑𝑎𝑡𝑎) − 𝑃𝐻2 𝑂 = 767.2 − 21.714 = 745.486 mmHg
𝑃𝐻2 𝑉𝐻2 = 𝑃(𝑑𝑎𝑡𝑎) 𝑉2
→ 𝑉2 =
𝑃𝐻2 𝑉𝐻2 745.486 𝑚𝑚𝐻𝑔 × 0.04210 L
=
= 0.040908447 𝐿
𝑃(𝑑𝑎𝑡𝑎)
767.2 𝑚𝑚𝐻𝑔
𝑃𝐻2 𝑉𝐻2 = 𝑛𝐻2 𝑅 𝑇(𝑑𝑎𝑡𝑎)
→ 𝑛𝐻2
745.486
( 760 atm) × (0.040908447 𝐿)
𝑃𝐻2 𝑉𝐻2
=
=
= 1.649235529 × 10−3 mol
𝑎𝑡𝑚. 𝐿
𝑅 𝑇(𝑑𝑎𝑡𝑎)
(0.08206
) × (296.5 K)
𝑚𝑜𝑙. 𝐾
𝑀 + 2𝐻𝐶𝑙 → 𝑀𝐶𝑙2 + 𝐻2
→ 𝑚𝑜𝑙 𝑀 = 𝑚𝑜𝑙 𝐻2 → 𝑀 =
𝑚
0.0415 g
𝑔
=
≈
25.16317
𝑛 1.649235529 × 10−3 mol
𝑚𝑜𝑙
Metal Identity: Magnesium (Mg)
Molar Volume Identify:
Volume of H2:
𝑃(𝑆𝑇𝑃) 𝑉𝐻2 𝑃𝐻2 𝑉(𝑑𝑎𝑡𝑎)
=
𝑇(𝑆𝑇𝑃)
𝑇(𝑑𝑎𝑡𝑎)
Page 4 of 6
NAME: HIEP TON
→ 𝑉𝐻2 =
February 2, 2015
𝑃𝐻2 𝑉(𝑑𝑎𝑡𝑎) 𝑇(𝑆𝑇𝑃) (745.486 mmHg) × (0.04210 L) × (273 𝐾)
=
= 0.038022961 L
(760 mmHg ) × (296.5 𝐾)
𝑃(𝑆𝑇𝑃) 𝑇(𝑑𝑎𝑡𝑎)
Mole of H2:
𝑀 + 2𝐻𝐶𝑙 → 𝑀𝐶𝑙2 + 𝐻2
→ 𝑚𝑜𝑙 𝐻2 = 𝑚𝑜𝑙 𝑀 = 1.649235529 × 10−3 mol
Molar Volume of H2:
→
𝑉
0.038022961 L
𝐿
=
= 23.0549
−3
𝑛 1.649235529 × 10 mol
𝑚𝑜𝑙
Percent Error:
% 𝐸𝑟𝑟𝑜𝑟 =
II.
(23.0549 − 22.4)
= 2.9236607%
22.4
POSTLAB QUESTIONS
1. If the metal strip had not been cleaned and an oxide film was left on the ribbon. Would the
volume of hydrogen gas generated be higher or lower than the true value? Explain.
Answer: If the oxide film was still on the ribbon, the volume of hydrogen gas generated
would be lower than the true value. It is because the O2 would try to get the H2
and form water . Therefore, the amount of H2 would be lower
Page 5 of 6
NAME: HIEP TON
February 2, 2015
2. If some air enters the eudiometer tube, what effect will it have on the atomic weight
determination?
Answer: The air will increase the mole. Then, the molar mass of the metal will be
decreased. Therefore, the metal cannot be determined correctly deal with the
incorrect lower molar mass from the data calculation.
3. What is the value of R in SI units?
Answer:
III.
𝐽
𝑘𝑔 . 𝐾
PEERS EVALUATION
Thi Bui
A
Very active, answer all the concerns and well communicated. Take
responsibility for the task assigned and finish early. Really involved
into group work.
Tuyet Mai Nguyen A
Not communicate well. Finish the task assigned and take care of
unfinished part early. Really involved into group work.
Jiale Yu
A
Finish the task assign and very helpful on calculation. Take
responsible to finish any unfinished part. Really involved into group
work.
John Schubert
F
Not active. Not finish anything.
Page 6 of 6