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Chemical Reactions

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Writing Reactions,Write balanced molecular equations for the two reactions you performed and the five reactions in the video (http://www.youtube.com/v/i-HHvx1VC_8&hl=en). Keep the following in mind:
- select the type of reaction.
- include all state symbols like (s), (l), (g), or (aq).
- Type NONE if there is no total or net ionic equation for the reaction.

(A) CuSO4(aq) + Al(s) --> ?
reaction type
• Molecular =
• total ionic =
• net ionic =

(B) CuSO4(aq) + CaCl2(aq) --> ?
reaction type
• Molecular =
• total ionic =
• net ionic =

(C) Watch the video (http://www.youtube.com/v/i-HHvx1VC_8&hl=en). Pause it as necessary. Write the appropriate reactions as you did for A and B. Type NONE if there is no total or net ionic equation.
i) Cu(s) + S(g) --> ?
reaction type
• Molecular =
• total ionic =
• net ionic =

ii) Ca(OH)2(s) --> ?
reaction type
• Molecular =
• total ionic =
• net ionic =

iii) Fe2O3(s) + Al(s) --> ?
TIP: What state is indicated by 'molten'?
reaction type
• Molecular =
• total ionic =
• net ionic =

iv) KI(aq) + Hg2(NO3)2(aq) --> ?
TIP: Mercury(I) actually forms a dimer and is typically found as Hg2+2. Treat it like a polyatomic ion.
reaction type
• Molecular =
• total ionic =
• net ionic =

v) CH4(g) + O2(g) --> ?
reaction type
• Molecular =
• total ionic =
• net ionic =

Results

For the following calculations, please note that you are starting with the hydrates of copper(II) sulfate (CuSO4.5H2O) and calcium chloride (CaCl2.2H2O). The waters will not affect the reactions, but they do affect the molar mass of the substance and therefore the moles of substance.

Reaction A
Calculate the theoretical mass of copper for Reaction A. (**Keep 2 significant figures here so that we can avoid rounding issues...Previously, I stated "round this mass to one decimal place since that is all the digital balance can measure" but that is not working.)

Calculate the percent yield of copper for Reaction A to two significant figures.

Reaction B
Calculate the theoretical mass of precipitate for Reaction B. (**Keep 2 significant figuress here so that we can avoid rounding issues...Previously, I stated "round this mass to one decimal place since that is all the digital balance can measure" but that is not working.)

Calculate the percent yield of precipitate for Reaction B to two significant figures.

List at least three errors that may have affected the percent yield.

Video Reactions - Observations
Describe each reaction. (What were the ways that you could tell a reaction was taking place? List the evidence for each reaction.
i) Cu(s) + S(s) --> ?
ii) Ca(OH)2(s) --> ?
iii) Fe2O3(s) + Al(s) --> ?
iv) KI(aq) + Hg2(NO3)2(aq) --> ?
v) CH4(g) + O2(g) --> ?

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https://brainmass.com/chemistry/inorganic-chemical-reactions/chemical-reactions-531799

Solution Preview

Write balanced molecular equations for the two reactions you performed and the five reactions in the video (http://www.youtube.com/v/i-HHvx1VC_8&hl=en). Keep the following in mind:
- select the type of reaction.
- include all state symbols like (s), (l), (g), or (aq).
- Type NONE if there is no total or net ionic equation for the reaction.

(A) CuSO4(aq) + Al(s) -->)
reaction type: Single Displacement Redox Reaction
• Molecular = 3CuSO4(aq) + 2Al(s) --> Al2(SO4)3(aq)+3Cu(s)
• total ionic =3Cu2+(aq) + 3SO42-(aq) + 2Al(s) = 2Al3+(aq) + 3SO42-(aq)+ 3Cu(s)
• net ionic =3Cu2+(aq) +2Al(s) = 2Al3+(aq) + 3Cu(s)

(B) CuSO4(aq) + CaCl2(aq) --> ?
reaction type: Precipitation Double Displacement Reaction
• Molecular = CuSO4(aq) + CaCl2(aq) -->CuCl2(aq) + CaSO4(s)
• total ionic = Cu2+(aq) + SO42-(aq) + Ca2+(aq)+2Cl-(aq) --> Cu2+(aq) +2Cl-(aq) +CaSO4(s)
• net ionic = Ca2+(aq) + SO42-(aq) --> CaSO4(s)

(C) Watch the video (http://www.youtube.com/v/i-HHvx1VC_8&hl=en). Pause it as necessary. Write the appropriate reactions as you did for A and B. Type NONE if there is no total or net ionic equation.
i) Cu(s) + S(g) --> ?
reaction type : Synthesis/Combination Redox Reaction
• Molecular = Cu(s) + S(g) --> CuS(s)
• total ionic =NONE
• net ionic = NONE

ii) Ca(OH)2(s) --> ?
reaction type: Decomposition Redox Reaction
• Molecular = Ca(OH)2(s) -->CaO(s) +H2O(l)
• total ionic = NONE
• net ionic = NONE

iii) Fe2O3(s) + 2Al(s) --> 2Fe (l)+ Al2O3(s)
TIP: What state is ...

Solution Summary

The expert writes reactions and balanced molecular equations for two reactions.

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General Chemistry

1. 4CuO(s) + CH4(g) CO2(g) + 4Cu(s) + 2H2O(g)
The value of Kc for this reaction is 1.10 at 25.0°C. What is the
value of Kp for this reaction? (R = 0.0821 L-atm/K-mol)

a. 4.63
b. 26.9
c. 658
d. 37.2
e. 1.52 x 10-3

2. At a certain temperature, a flask at equilibrium contains 0.0551 M
HCl, 0.112 M Cl2, and 0.105 M H2. What is the value of Kc for the
equilibrium: 2 HCl(g) → Cl2(g) + H2(g)?

a. 3.87
b. 0.258
c. 11.0
d. 1.63 x 10-5
e. 0.213

3. Consider the following incomplete table of data for the equilibrium
between dinitrogen tetroxide and nitrogen dioxide.

Exp # Equilibrium N2O4 Concentr Equilibrium NO2 Concentration
1 0.00140 M 0.0172 M
2 0.00452 ?
3 0.00280 0.0243

From the information in the table, determine the value of the
missing NO2 concentration at equilibrium.

a. 0.0309
b. 0.0486
c. 9.54 x 10-4
d. 0.115
e. 0.0814

3. Consider the gaseous equilibrium: 2 A → 2 B + C
Determine the value of the missing B concentration at equilibrium.

Exp# [A] at equilibrium [B] at equilibrium [C] at equilibrium
1 0.10 M 0.15 M 0.20 M
2 0.20 0.50 0.072
3 0.35 ? 0.15

a. 0.20
b. 0.35
c. 0.61
d. 0.40
e. 0.37

4. The expression for Kc for the reaction below is _______________.
NiCO3(s) + 2H+(aq) Ni2+(aq) + CO2(g) + H2O(l)

a. [CO2]
b. [NiCO3]/[Ni2+]
c. [Ni2+][CO2]/[H+]2
d. [Ni2+][H+]2
e. [Ni2+]/[NiCO3]

5. Consider the following chemical reaction:
H2(g) + I2(g) 2HI(g)
At equilibrium, the concentrations of H2, I2, and HI were 0.15 M,
0.033 M, and 0.55 M, respectively. The value of Kc for this reaction
is
111
9.0 x 10-3
6.1
23
61

6. Consider the following reaction:

PCl5(g) PCl3(g) + Cl2(g)

Initially, 0.84 mol of PCl5(g) was placed in a 1.0 L flask. At
equilibrium, 0.72 mol of PCl5(g) was present. The value of Kc for
this reaction at this temperature is ___________.

a. 2.0 x 10-2
b. 0.62
c. 0.60
d. 0.12
e. 0.72

7. The value of Kc for the reaction below is 0.016. Under a set of
equilibrium conditions, [HI] = 0.10 M and [H2] = [I2]. Calculate the
concentration of I2 (M).
2HI(g) H2(g) + I2(g)

a. 1.3 M
b. 3.1 x 10-1
c. 0.31
d. 4.0 x 10-2
e. 1.3 x 10-2

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