What volume (to the nearest 0.1 mL) of 7.10-M HCl must be added to 0.550 L of 0.350-M K2HPO4 to prepare a pH = 7.50 buffer?
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Calculate the pH change that results when 12 mL of 2.8 M HCl is added to 580. mL of each of the following solutions. Use the Acid-Base Table. Please see pH changes - part a and b and pH changes - part c and d for assistance.
(a) pure water
(b) 0.10 M CH3COO−
(c) 0.10 M CH3COOH
(d) a solution that is 0.10 M in each CH3COO− and CH3COOH.
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A 5.079 g sample of a solid, weak, monoprotic acid is used to make a 100.0 mL solution. 26.00 mL of the resulting acid solution is then titrated with 0.09454 M NaOH. The pH after the addition of 18.00 mL of the base is 5.54, and the endpoint is reached after the addition of 47.60 mL of the base. Please see Titration to Determine Molecular Weight for assistance.
(a) How many moles of acid were present in the 26.00 mL sample? mol
(b) What is the molar mass of the acid? g/mol
(c) What is the pKa of the acid?
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If the Kb of a weak base is 3.2 × 10^-6, what is the pH of a 0.50 M solution of this base?
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Aqueous solutions of lead(II) nitrate and potassium bromide are mixed together. (The solution turns cloudy white during the re
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How was excess NaOH avoided in the separated solid soap?
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calculate the pH of the following aqueous solution at 25 degreesCelsius and .35M NaF (pKa for HF=3.14)
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Write the z-matrix for Coronene. Assume all Carbon-Carbon bond lengths to be 1.40 Angstroms and all Carbon-Hydrogen bond lengths to be 1.07 Angstroms. Include the connectivity table.
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Extraction of Trimyristin from Nutmeg Lab
1. Why is acetone a good solvent to recrystallize the trymyristin? What are the disadvantages?
2. Assume that the amount of trimyristin in nutmeg is 20% by weight. What would be the expected amount to be recovered from the 7.00g of nutmeg?
3. Calculate your percent recovery using the expected recovery amount (expected 20% of the sample you weighed).
4.If the melting point of the purified trimyristin was done before it was completely dry what would be the effect on the melting point and why?
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The formula for methane is CH4 and it’s molar mass is 16.04 grams/mol.
(a) How many moles of methane are in 2.750 grams of methane?
(b) How many molecules of methane are in a 11.5 mole sample?
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Why is it not necessary to test the reactivity of the elemental metals with solutions of the same metal ion? To illustrate your explanation, write the equation for the potential chemical reaction using one of the metals: Cu, Zn, Mg, Ni, Pb.
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Now that Hermione understands empirical formulas she wants to teach Harry and Ron. What is the empirical formula for dibromoethane: C2H4Br2
A. CH2Br2
B. CH2Br
C. C2H4Br
D. CHBr
E. C2H2Br2
2.Calculate the maass percent composition of carbon in C2H5Cl.
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5. Describe qualitatively the microstructural development that will occur upon slow cooling from of 1050 steel from 1600 °C to 20 °C.
6.
a). What are p-type semiconductors? What are their differences comparing with n-type semiconductors?
b). Moore’s law predicts the rapid and steady growth in the number of transistors contained on a single microcircuit chip. Why do engineers want to increase the number of transistors contained on a single microcircuit chip?
c). Even through silicon is abundant on the earth. What is the key reason that silicon wafers are so expensive?
d). Based on the semiconductor introduction video, if the thickness of a semiconductor wafer is ___ _ floor height, the Integrated Circuits are build on the top ____ floor(s).
7.
a). Among multiple components of a composite material, at least two components have to serve for specific functions. What are these two components? What are these two specific function?
b). Give an example of engineering application (not household items), where ceramics will be good materials to choose and high alloy steel will not be a good material to choose. Explain your reasons.
c). Give an example of engineering application (not household items), where polymers will be good materials to choose and composites will not be a good material to choose. Explain your reasons.
8.
a). Among many polymer processes, which processes can be usefor thermoplastics? Can they be used to process thermosetting polymers? Explain your reasons.
b). Engineering designers select thermosetting polymers to make electrical components. Explain why not use thermoplastic polymers.
c). PVC popes are widely used in commercial and residential construction, what does PVC stands for?
In: Chemistry
The solubility product for barium sulfate is 1.1*10^-10. Calculate the molar solubility of barium sulfate.
1) 5.5*10^-11 mol/L
2) 1.1 *10^-5 mol/L
3) 2.1*10^-5 mol/L
4) 1.1*10^-10 mol/L
5) 2.2*10^-10 mol/L
I don't understand how to solve this. I'm stuck. Can anyone help me soon as possible as fast? Thank you.
In: Chemistry
Calculate the pH, pOH, [H3O+], and [OH-] of the following
solutions:
(a) 0.001 M HNO3,
(b) 0.3 M Ca(OH)2;
(c) 3.0 M HNO3,
(d) 6.0 M NaOH,
(e) 0.05 M HBr
In: Chemistry