Balancing Redox Reactions: Acidic Solutions

Consider the reaction of 3.0 M dichromate: Cr2O7 2–      →       Cr3+ (Acidic Medium). What would be the coefficient on water in the balanced equation? a. 7 b. 5 c. 6 d. 4

Consider the equation: Cr2O7 2 – + H + + I –       →      Cr 3+ (aq) + H2O + I 3 – Which coefficient would be needed to balance I –? a) 9               b) 7               c) 5               d) 14

When concentrated H2SO4 (l) is added to I - (aq), I 2 (s) and H2S (g) are formed. When the equation for this reaction is balanced, what is the number of electrons transferred?   a) 8 b) 2 c) 4 d) 6 e) 1 

When the following redox equation is balanced with smallest whole-number coefficients, the coefficient for zinc will be. Zn(s) + ReO4-(aq) → Re(s) + Zn2+(aq) (acidic solution) A) 2 B) 7 C) 8 D) 16 E) None of these choices is correct.

How many electrons are transferred in the following reaction after balancing? (The reaction is unbalanced!) Mg(s) + Al 3+(aq) → Al (s) + Mg2+(aq) A) 1 B) 2 C) 3 D) 4 E) 6

Predict the formula for magnesium phosphide. What is the total number of electrons transferred?a. Mg2P3 ; 3 electrons are transferred from Mg to Pb. Mg3P2 ; 6 electrons are transferred from Mg to Pc. Mn3P ; 3 electrons are transferred from P to Mnd. MgP3 ; 6 electrons are transferred from Mg to Pe. MgP2 ; 4 electrons are transferred from P to Mg

What is the coefficient of the permanganate ion (MnO 4−) when the following equation is balanced? MnO4− + Br − → Mn2+ + Br2          (acidic solution) A) 3                        B) 4                 C) 2                 D) 1                 E) 5

Balance the following redox reaction in acidic conditions, listing the half reactions for oxidation and reduction. Also list the oxidation states of atoms in reaction.

Balance the following reaction in acidic solution and determine the coefficient of H + and its location (reactant or product side) in the overall reaction. HNO2 (aq) + HClO2 (aq) → N2O (aq) + ClO3– (aq) a) 2, reactant b) 4, reactant c) 6, product d) 4, product e) 2, product

Consider the unbalanced redox reaction:MnO4–(aq) + Zn(s) → Mn2+(aq) + Zn2+(aq)Balance the equation and determine the volume of a 0.500 M KMnO 4 solution required to completely react with 2.85 g of Zn.

A sample of impure tin of mass 0.535 g is dissolved in strong acid to give a solution of Sn2+. The solution is then titrated with a 0.0448 M solution of NO 3-, which is reduced to NO(g). The equivalence point is reached upon the addition of 0.0344 L of the NO3- solution. Find the- percent by mass of tin in the original sample, assuming that it contains no other reducing agents.

When this oxidation-reduction equation is the balanced in acidic solution, using only whole number coefficients, what is the coefficient for S(s)? ? Cr2O72- (aq) + ? H2S (aq) → ? Cr3+ (aq) + ? S (s)(A) 4(B) 3(C) 2(D) 1

Balance the following redox reaction in the order it is written:___Fe + ___ I 2  →  ___ Fe 3+ + ___ I –a. 1,1,1,2b. 1,3,1,6c. 3,3,3,6d. 2,1,2,2e. 2,3,2,6

Balance the following equation:Cu(s) + H+(aq) + NO3-(aq) → NO(g) + H2O(l) + Cu2+(aq)The coefficients are:A) 1,2,1,1,1,1B) 3,2,1,1,1,3C) 3,4,2,2,4,3D) 1,8,2,2,4,1E) 3,8,2,2,4,3

What is the coefficient of aluminum when the following reaction is balanced?    Pt2+ + Al → Al 3+ + Pt A) 1 B) 2 C) 3 D) 4 E) 6

For the oxidation-reduction reaction equation given here,2Li + Se → Li 2SeIndicate how many electrons are transferred in the formation of one formula unit of product?

Complete and balance the equation for this reaction in acidic solution.MnO4- + HNO2 → NO3 - + Mn2+i) Which element got oxidized?ii) Which element got reduce?iii) Which species was the oxidizing agent?iv) Which species was the reducing agent?

For the oxidation-reduction reaction equation given below, indicate how many electrons are transferred in the formation of one formula unit of product.2Na + S → Na 2S 

In the process of oxidizing I - to I2, SO42- is reduced to SO2. How many moles of SO2 are produced in the formation of one mole of I 2?Express your answer numerically in moles.

For the oxidation-reduction reaction equation given here,2K + F2 → 2KFindicate how many electrons are transferred in the formation of one formula unit of product.

For the oxidation-reduction reaction equation given here4Ga + P4 → 4GaPIndicate how many electrons are transferred in the formation of one formula of product.

Consider the reaction at 55°C, where [Fe2+] = 3.80 M and [Mg2+] = 0.310 M Mg(s) + Fe2+(aq) → Mg+2(aq) + Fe(s)                      What is the value for n?

How many electrons are transferred in the following reaction? (The reaction is unbalanced.) Mg (s) + Al 3+(aq) → Al(s) + Mg 2+(aq)a. 6b. 2c. 3d. 1e. 4

Consider the unbalanced redox reaction:Cr2O72–(aq) + Cu(s) → Cr 3+ (aq) + Cu 2+(aq)Balance the equation and determine the volume of a 0.850 M K2Cr2O7 solution required to completely react with 5.25 g of Cu. 

Complete and balance the equation for this reaction in acidic solution.ZnS + NO3- → Zn2+ + S + NO i) Which element got oxidized?ii) Which element got reduced?iii) Which species was the oxidizing agent?iv) Which species was the reducing agent?

For the oxidation-reduction reaction equation given here,2Rb + Br2 → 2RbBrIndicate how many electrons are transferred in the formation of one formula unit of product.