Question
How much K2Cr2O7 must be weighed and dissolved in distilled water to prepare 250 mL of a 2 mol/L solution?
108
likes541 views
Answer to a math question How much K2Cr2O7 must be weighed and dissolved in distilled water to prepare 250 mL of a 2 mol/L solution?
Rasheed
4.7109 Answers
1. Determine the molar mass of K_2Cr_2O_7
M(K_2Cr_2O_7) = 2(39.1) + 2(52.0) + 7(16.0) = 294.2 \text{ g/mol}
2. Calculate the number of moles needed to prepare 250 mL (0.25 L) of a 2 mol/L solution:
n = C \cdot V = 2 \text{ mol/L} \times 0.25 \text{ L} = 0.5 \text{ mol}
3. Calculate the mass ofK_2Cr_2O_7
m = n \cdot M = 0.5 \text{ mol} \times 294.2 \text{ g/mol} = 147.1 \text{ g}
2. Calculate the number of moles needed to prepare 250 mL (0.25 L) of a 2 mol/L solution:
3. Calculate the mass of
Frequently asked questions (FAQs)
Math question: Solve the cubic equation x^3 - 5x^2 + 2x = 3.
+
What is the standard deviation of a set of numbers: 4, 6, 8, 10, 12?
+
Question: The scores of 25 students on a test are as follows: 84, 92, 78, 72, 92, 88, 80, 88, 86, 84, 92, 78, 82, 94, 86, 78, 92, 80, 98, 88, 90, 78, 84, 94, 82. What is the median score?
+
New questions in Mathematics