Problem 2: Chemical Equation Balancing The dissolution of copper sulfide in aque

Question

Problem 2: Chemical Equation Balancing The dissolution of copper sulfide in aqueous nitric acid is described by the following chemical reaction equation: where the coefficients a through g are the numbers of the various molecules participating in the reaction and are unknown. Balancing each atom in the reaction between the left and right sides of the reaction equation, and the ionic charge results in the following system of equations: a=d 3b = 4e +f+g -b + c = 2d-2e Since there is one more unknown than equations, a solution can be found through an iterative approach because we know that all of the coefficients must be positive integers. Start by assigning a-1 and solving the system, if the calculated coefficients are all positive integers you have a solution, if there is either a negative value or decimal/fraction then re-assign a 2 and continue until you find all positive integer coefficients, or find the scalar multiple to create all coefficients to be integers.

Explanation / Answer

Ans. With a =1

            a = d = e = 1             -equation 1

            3b = 4e + f + g         - equation 2

            c = 2g                         - equation 3

            -b + c = 2d – 2e        - equation 4

            b = f                            - equation 5

# Comparing equation 4 and 1-

            -b + c = (2 x 1) – (2 x 1)                               ; [d = e =1 -equation 1]

            Or, c – b = 0

            Or, c = b                    - equation 6

# Comparing equation 2 and 3

            3b = 4e + f + 0.5c = (4 x 1) + b + 0.5b                 ; [b= c ; b = f]

            Or, 3b = 4 + 1.5b

            Or, 3b - 1.5 b = 4

            Or, b = (4 / 1.5)

To make “b” a positive whole number integer, it must be multiplied with the factor “3”, so that all other coefficients become an integer.

            Or, b = (4 / 1.5) x 3 = 8

            Hence, b = 8

# Since, “b is multiplied by 3” the value of “a” must also be multiplied by same factor to yield the same stoichiometric ratio.

So,       Overall coefficients are –

            a = d = e = 1 x 3 = 3

            b = c = f = 8

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.