Zinc metal reacts with hydrochloric acid according to the balanced equation: Zn ( s ) + 2 HCl ( aq ) → ZnCl 2 ( aq ) +H 2 ( g ) When 0.103 g of Zn(s) is combined with enough HCI to make 50.0 mL of solution in a coffee-cup calorimeter, all of the zinc reacts, raising the temperature of the solution from 22.5 °C to 23.7 °C. Find Δ H rxn for this reaction as written. (Use 1.0 g/mL for the density of the solution and 4.18 J/g °C as the specific heat capacity.)
Zinc metal reacts with hydrochloric acid according to the balanced equation: Zn ( s ) + 2 HCl ( aq ) → ZnCl 2 ( aq ) +H 2 ( g ) When 0.103 g of Zn(s) is combined with enough HCI to make 50.0 mL of solution in a coffee-cup calorimeter, all of the zinc reacts, raising the temperature of the solution from 22.5 °C to 23.7 °C. Find Δ H rxn for this reaction as written. (Use 1.0 g/mL for the density of the solution and 4.18 J/g °C as the specific heat capacity.)
Solution Summary: The author calculates the enthalpy change of a reaction by applying the law of conservation of energy.
Zinc metal reacts with hydrochloric acid according to the balanced equation:
Zn
(
s
)
+ 2 HCl
(
aq
)
→
ZnCl
2
(
aq
)
+H
2
(
g
)
When 0.103 g of Zn(s) is combined with enough HCI to make 50.0 mL of solution in a coffee-cup calorimeter, all of the zinc reacts, raising the temperature of the solution from 22.5 °C to 23.7 °C. Find
Δ
H
rxn
for this reaction as written. (Use 1.0 g/mL for the density of the solution and 4.18 J/g °C as the specific heat capacity.)
ion.
A student proposes the following Lewis structure for the perchlorate (CIO) io
:
:0:
: Cl
:
-
-
:
:0:
ك
Assign a formal charge to each atom in the student's Lewis structure.
atom
central O
formal charge
☐
top O
☐
right O
☐
bottom O
☐
Cl
☐
Decide whether these proposed Lewis structures are reasonable.
proposed Lewis structure
Yes.
Is the proposed Lewis structure reasonable?
Cl-
: 2:
:Z:
:Z:
N—N
: 0:
C C1:
O CO
No, it has the wrong number of valence electrons.
The correct number is: ☐
No, it has the right number of valence electrons but doesn't satisfy the
octet rule.
The symbols of the problem atoms are:* ☐
Yes.
No, it has the wrong number of valence electrons.
The correct number is: ☐
No, it has the right number of valence electrons but doesn't satisfy the
octet rule.
The symbols of the problem atoms are:* |
Yes.
No, it has the wrong number of valence electrons.
The correct number is:
No, it has the right number of valence electrons but doesn't satisfy the
octet rule.
The symbols of the problem atoms are:* |
If two or more atoms of the same element don't satisfy the octet rule, just enter the chemical symbol as many
times as necessary. For example, if two oxygen atoms don't satisfy the octet rule, enter "0,0".
☑
Use the observations about each chemical reaction in the table below to decide the sign (positive or negative) of the reaction enthalpy AH and reaction entropy
AS.
Note: if you have not been given enough information to decide a sign, select the "unknown" option.
reaction
observations
conclusions
ΔΗ is
(pick one)
A
This reaction is faster above 103. °C than
below.
AS is
(pick one)
ΔΗ is
(pick one)
B
This reaction is spontaneous only above
-9. °C.
AS is
(pick one)
ΔΗ is
(pick one)
C
The reverse of this reaction is always
spontaneous.
AS is
(pick one)
18
Ar
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, chemistry and related others by exploring similar questions and additional content below.
Author:Steven D. Gammon, Ebbing, Darrell Ebbing, Steven D., Darrell; Gammon, Darrell Ebbing; Steven D. Gammon, Darrell D.; Gammon, Ebbing; Steven D. Gammon; Darrell
Author:Steven D. Gammon, Ebbing, Darrell Ebbing, Steven D., Darrell; Gammon, Darrell Ebbing; Steven D. Gammon, Darrell D.; Gammon, Ebbing; Steven D. Gammon; Darrell
Calorimetry Concept, Examples and Thermochemistry | How to Pass Chemistry; Author: Melissa Maribel;https://www.youtube.com/watch?v=nSh29lUGj00;License: Standard YouTube License, CC-BY