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)
Question: What is the derivative of the hyperbolic cosine function (cosh(x))?
+
What is the equation for the distance between two points (x1,y1) and (x2,y2) on a coordinate plane?
+
What is the measure of angle C if side a has length 5, side b has length 8, and the angle between them is 45 degrees?
+
New questions in Mathematics
1 + 1
-6n+5=-13
5(4x+3)=75
Find the equation of the normal to the curve y=x²+4x-3 at point(1,2)
how many arrangement can be made of 4 letters chosen from the 8 letters of the world ABBSOLUTE
By direct proof, how can you prove that “The sum of any three consecutive even integers is always a multiple of 6”.
5.- From the probabilities: 𝐏(𝐁) = 𝟑𝟎% 𝐏(𝐀 ∩ 𝐁) = 𝟐𝟎% 𝐏(𝐀 ̅) = 𝟕𝟎% You are asked to calculate: 𝐏(𝐀 ∪ 𝐁)
If 0101, what is the binary representation of the 4x16 decoder output?
What is 28 marks out of 56 as a percentage
Two business partners have a bank balance of $17,942.00. After the first year their interest brings their balance to $18,928.91. What rate of interest is earned?
suppose random variable x follows poisson distribution with expected value 3. what is variance of x?
Calculate the value of a so that the vectors (2,2,−1),(3,4,2) and(a,2,3) are coplanar.
From 1975 through 2020 the mean annual gain of the Dow Jones Industrial Average was 652. A random sample of 34 years is selected from this population. What is the probability that the mean gain for the sample was between 400 and 800? Assume the standard deviation is 1539
effectiveness of fiscal and monetary policy under closed and open economies
A diamond ring was reduced from $999.99 to $689.99. Find the percent reduction in the price. Round the answer to the nearest tenth of a percent, if necessary.
Calculate the area of the parallelogram with adjacent vertices (1,4, −2), (−3,1,6) 𝑦 (1, −2,3)
What is the total amount due and the amount of interest on a 3-year loan of $1,000 at a simple interest rate of 12% per year?
22. Let [AB] be a chord in a circle C, and k a circle which is internally tangent to the circle C at a point P and to the chord [AB] at a point Q. Show that the line P Q passes through the midpoint of the arc AB opposite to the arc APB.
5a-3.(a-7)=-3
f(x)= 9-x^2 find (f(x+h)-f(x) )/h