Question

Potassium dichromate, also called potassium bichromate, is an orange-red crystalline solid, K2Cr2O7, soluble in water and insoluble in alcohol. What is the molar concentration of this salt in a solution whose chromium ion concentration is 5.72 mg/mL? Data: K=39; Cr=52 and O=16 g/mol. NOTE: The answer must have 3 places after the comma, to avoid rounding errors.

55

likes
275 views

Answer to a math question Potassium dichromate, also called potassium bichromate, is an orange-red crystalline solid, K2Cr2O7, soluble in water and insoluble in alcohol. What is the molar concentration of this salt in a solution whose chromium ion concentration is 5.72 mg/mL? Data: K=39; Cr=52 and O=16 g/mol. NOTE: The answer must have 3 places after the comma, to avoid rounding errors.

Expert avatar
Santino
4.5
112 Answers
\text{Concentração de íons crômio em g/L} = 5.72 \times 10^{-3} \, \text{g/mL} \times 1000 \, \text{mL/L}

\text{Concentração de íons crômio em g/L} = 5.72 \, \text{g/L}

\text{Massa molar de } Cr = 52 \, \text{g/mol}

\text{Número de mols de } Cr = \frac{5.72 \, \text{g/L}}{52 \, \text{g/mol}}

\text{Número de mols de } Cr = 0.110 \, \text{mol/L}

K_2Cr_2O_7 \rightarrow 2K^+ + 2Cr^{3+} + 7O^{2-}

[Cr^{3+}] = 2 [K_2Cr_2O_7]

0.110 \, \text{mol/L} = 2 [K_2Cr_2O_7]

[K_2Cr_2O_7] = \frac{0.110}{2} \, \text{mol/L}

[K_2Cr_2O_7] = 0.055 \, \text{mol/L}

\text{Answer: } 0.055 \, \text{mol/L}

Frequently asked questions (FAQs)
What is the equation of a hyperbola with center (0,0), asymptotes y = 2x and y = -2x, and foci (-3,0) and (3,0)?
+
Math Question: Find the absolute extrema of the function f(x) = 2x^3 - 12x^2 + 15x - 7 on the interval [0, 5].
+
What is the 6th derivative of f(x) = 5x^3 - 8x^2 + 2x + 2?
+
New questions in Mathematics
A car tire can rotate at a frequency of 3000 revolutions per minute. Given that a typical tire radius is 0.5 m, what is the centripetal acceleration of the tire?
5) A family with a father, mother and 3 children must sit on five chairs in a row and the only restriction is that the mother must be at one end. In how many different ways can they be seated?
Determine the correct value: A company knows that invoices pending collection have a normal distribution with a mean of $1.65 million, with a standard deviation of $0.2 million, then: The probability that an invoice pending collection has an amount that is within more than 2 deviations below the mean, is:
Evaluate limx→∞tan−1(x) using that y=tan−1(x) exactly when x=tan(y) . (Hint: Both tan and tan−1 are continuous!)
By differentiating the function f(x)=(x³−6x)⁷ we will obtain
(m²-121)
(6.2x10^3)(3x10^-6)
In a store there are packets of chocolate, strawberry, tutti-frutti, lemon, grape and banana sweets. If a person needs to choose 4 flavors of candy from those available, how many ways can they make that choice?
Equivalent expression of the sequence (3n-4)-(n-2)
A National Solidarity Bond offers A 5 year bond offering a gross return of 15% Calculate the AER for this investment. (Give your answer to two decimal places, no need for the percent or € sign in your answer)
A construction company is working on two projects: house construction and building construction. Each house requires 4 weeks of work and produces a profit of $50,000. Each building requires 8 weeks of work and produces a profit of $100,000. The company has a total of 24 work weeks available. Furthermore, it is known that at least 2 houses and at least 1 building must be built to meet the demand. The company wants to maximize its profits and needs to determine how many houses and buildings it should build to meet demand and maximize profits, given time and demand constraints.
v Is the following statement a biconditional? If Shannon is watching a Tigers game, then it is on television.
Primes are numbers divisible only by 1 and themselves; There are infinitely many prime numbers and the first ones are 2, 3, 5, 7, 11, 13, 17, 19, 23, .... Consider a 12-sided die, with the faces numbered from 1 to 12. Out of 4 rolls, the probability that only the first three numbers are primes is:
The sum of two numbers is 144. Double the first number minus thrice the second number is equal to 63. Determine the first two numbers.
For what values of m is point P (m, 1 - 2m) in the 2⁰ quadrant?
Find the number of pounds of nails required for 17850 square feet of drywall if each thousand square feet requires 4.5 pounds of nails.
factor the polynomial completely over the set of complex numbers b(x)=x^4-2x^3-17x^2+4x+30
A 20,000 kg school bus is moving at 30 km per hour on a straight road. At that moment, it applies the brakes until it comes to a complete stop after 15 seconds. Calculate the acceleration and the force acting on the body.
Perform operations with the polynomials P(x) = x3 and Q(x) = 2x2 + x – 3x3 : a) P(x) - Q(x)
A plant found at the bottom of a lake doubles in size every 10 days. Yeah It is known that in 300 days it has covered the entire lake, indicate how many days it will take to cover the entire lake four similar plants.