HW7-M2.1-Ch5

Methanol, CH3OH, has been suggested as an alternative to gasoline as an automotive fuel. Write a balanced chemical equation for its complete combustion. Include physical states in your answer.

2CH3OH(l) + 3O2(g) -> 2CO2(g) + 4H2O(g)

Use the table below to predict the outcome of the following reactions. Note: If no reaction occurs, enter unbalanced left part of the equation and then click "NR" on your ChemPad palette. Do not use the keyboard to enter physical states and "NR". If a reaction occurs, enter a balanced chemical equation for it. Cr + Pb2+ ->

2Cr + 3Pb^2+ -> 2Cr^3+ + 3Pb

Complete and balance the following if a reaction occurs. Write your answer as net ionic equation and include physical states of all compounds (including for water). If no reaction occurs write the left part of reaction and then click "NR". Ag(s) + Cu2+(aq)

Ag(s) + Cu2+(aq) -> NR

Complete and balance the following if a reaction occurs. Write your answer as net ionic equation and include physical states of all compounds (including for water). If no reaction occurs write the left part of reaction and then click "NR". Solid copper is added to aqueous concentrated nitric acid

Cu(s) + 4H+(aq) + 2NO3-(aq) -> Cu2+(aq) + 2NO2(g) + 2H2O(l)

2HNO3 + 3H3AsO3 2NO + 3H3AsO4 + H2O

H3AsO3; HNO3; HNO3; H3AsO3

HOF

H: 1 O: 0 F: -1

OF2

O: 2 F: -1

Sr(BrO3)2

Sr: 2 Br: 5 O: -2

Cl-

-1

electron transfer:

-oxidation is the loss of one or more electrons. -reduction is the gain of one or more electrons.

oxidation numbers:

-reduction is a decrease in oxidation number. -oxidation is an increase in oxidation number.

What is an oxidizing agent? What happens to it in a redox reaction? Select all that apply.

-the substance that accepts the electrons in the redox reaction -it gets reduced

What is a reducing agent? What happens to it in a redox reaction? Select all that apply.

-the substance that supplies the electrons in a redox reaction -it gets oxidized

Why must both oxidation and reduction occur simultaneously during a redox reaction? Select all that apply.

-the total number of electrons lost by one substance is the same as the total number gained by the other substance -electrons would appear as a product of the overall reaction, which is never observed

Use the table below to predict the outcome of the following reactions. Note: If no reaction occurs, enter unbalanced left part of the equation and then click "NR" on your ChemPad palette. Do not use the keyboard to enter physical states and "NR". If a reaction occurs, enter a balanced chemical equation for it. Ag+ + Fe->

2Ag^+ + Fe -> Fe^2+ + 2Ag

Metals below hydrogen in following table react with water. Enter balanced equations for each of these reactions. Include physical states for all species. Cesium

2Cs(s) + 2H2O(l) -> 2CsOH(aq) + H2(g)

Balance these equations for reactions occurring in an acidic solution. NO3- + Cu NO2 + Cu2+

2NO3- + Cu + 4H+ -> 2NO2 + CU2+ + 2H2O

Metals below hydrogen in the following table react with water. Enter balanced equations for each of these reactions. Include physical states for all species. Sodium

2Na(s) + 2H2O(l) -> 2NaOH(aq) + H2(g)

Balance these equations for reactions occurring in an acidic solution. S2O32- + OCl- Cl- + S4O62-

2S2O3^2- + OCl^- +2H^+ -> Cl^- + S4O6^2- + H2O

Use the table below to predict the outcome of the following reactions. Note: If no reaction occurs, enter unbalanced left part of the equation and then click "NR" on your ChemPad palette. Do not use the keyboard to enter physical states and "NR". If a reaction occurs, enter a balanced chemical equation for it. Ag + Au3+ ->

3Ag + Au^3+ -> 3Ag^+ + Au

6H2SO4 + 2Al Al2(SO4)3 + 3SO2 + 6H2O

Al; H2SO4; H2SO4; Al

Au(NO3)3

Au: 3 N: 5 O: -2

Which one of the following is not a redox reaction?

Ba(NO3)2(aq) + Na2CrO4(aq) -> BaCrO4(s) + 2NaNO3(aq)

Metals below hydrogen in following table react with water. Enter balanced equations for each of these reactions. Include physical states for all species. Bariuim

Ba(s) + 2H2O(l) -> Ba(OH)2(aq) + H2(aq)

Chlorine dioxide, ClO2 , is used to kill bacteria in the dairy industry, meat industry, and other food and beverage industry applications. It is unstable, but can be made by the following reaction:Cl2 + 2NaClO2 → 2ClO2 + 2NaClIdentify the substances oxidized and reduced, as well as the oxidizing and reducing agents in the reaction. Cl2 NaClO2

Cl2 is reduced and is the oxidizing agent NaClO2 is oxidized and is the reducing agent

ClO4-

Cl: 7 O: -2

Cr2S3

Cr: 3 S: -2

The following chemical reactions are observed to occur in aqueous solution. Arrange the metals Al, Pb, Fe, and Cu in order of increasing ease of oxidation.

Cu < Pb < Fe < Al

Use the table below to predict the outcome of the following reactions. Note: If no reaction occurs, enter unbalanced left part of the equation and then click "NR" on your ChemPad palette. Do not use the keyboard to enter physical states and "NR". If a reaction occurs, enter a balanced chemical equation for it. Fe + Mn2+ ->

Fe + Mn^2+ -> NR

2KMnO4 + 5H2C2O4 + 3H2SO4 10CO2 + K2SO4 + 2MnSO4 + 8H2O

H2C2O4; KMnO4; KMnO4; H2C2O4

Balance these equations for reactions occurring in an acidic solution. IO3- + H3AsO3 I- + H3AsO4

IO3- + 3H3AsO3 -> I- + 3H3AsO4

NaI + 3HOCl NaIO3 + 3HCl

NaI; HOCl; HOCl; NaI

When potassium reacts with molecular oxygen, O2 , the product is potassium peroxide, K2O2 , which contains the peroxide ion, O22-. In this reaction, is O2 oxidized or reduced?

O2 is reduced

Metals below hydrogen in following table react with water. Enter balanced equations for each of these reactions. Include physical states for all species. Radium

Ra(s) + 2H2O(l) -> Ra(OH)2(aq) + H2(g)

SF6

S: 6 F: -1

Balance these equations for reactions occurring in an acidic solution. SO42- + Zn Zn2+ + SO2

SO4-2 + Zn + 4H+ -> Zn+2 + SO2 + 2H2O

Complete and balance the following if a reaction occurs. Write your answer as net ionic equation and include physical states of all compounds (including for water). If no reaction occurs write the left part of reaction and then click "NR". Sn(s) + HCl(aq) ->

Sn(s) + 2H+(aq) -> Sn2+(aq) + H2(g)

The following equation is not balanced. Ag + Fe2+ → Ag+ + Fe

The total charge on both sides of the equation is unequal 2Ag + Fe^2+ -> 2Ag+ + Fe

Complete and balance the following if a reaction occurs. Write your answer as net ionic equation and include physical states of all compounds (including for water). If no reaction occurs write the left part of reaction and then click "NR". Zn(s) + Cu2+(aq)

Zn(s) + Cu2+(aq) -> Zn2+(aq) + Cu(s)

Which metals in the table below will not react with nonoxidizing acids?

gold mercury silver copper

Are the following redox reactions? Explain. (a) 2NO2 → N2O4 (b) 2CrO42- + 2H+ → Cr2O72- + H2O

neither reaction (a), nor reaction (b) are redox reactions, since the elements in these reactions do not change oxidation state.

If the oxidation number of nitrogen in a certain molecule changes from +3 to -3 during a reaction, is the nitrogen oxidized or reduced? How many electrons are gained (or lost) by each nitrogen atom?

reduced 6

If a metal is able to react with a solution of HCl, where must the metal stand relative to hydrogen in the activity series?

the metal must be BELOW hydrogen in the activity series

What are the net charges on the left and right sides of the following equations? Add electrons as necessary to make each of them a balanced half-reaction. Enter your answer as 1+ for the positive one. Cl2 + 4H2O -> 2ClO2- + 8H+

total charge on left: 0 total charge on right: 6 half-reaction: Cl2 + 4H2O -> 2ClO2- + 8H+ + 6e-

What are the net charges on the left and right sides of the following equations? Add electrons as necessary to make each of them a balanced half-reaction. Enter your answer as 1+ for the positive one. NO3- + 1OH+ -> NH4+ + 3H2O

total charge on left: 9 total charge on right: 1 half-reaction: NO3- + 10H+ + 8e- -> NH4+ + 3H2O