|
Weight of Unknown #4( in g) |
Volume of water (in mL) |
Unknown #4 solution (in g/L) |
|
0.118 |
50.00 |
2.36 |
|
0.127 |
50.00 |
2.54 |
|
0.112 |
50.00 |
2.24 |
Volume of NaOH used = Final concentration – Initial concentration
= 16.49 mL – 4.90 mL = 11.49mL NaOH= 0.01149 L NaOH
|
Exp. # |
Concentration of NaOH |
Initial volume of NaOH |
Final volume of NaOH |
Volume of NaOH used for titration |
|
1 |
0.1030M |
4.90mL |
16.49mL |
11.59mL |
|
2 |
0.1030M |
16.49mL |
26.01mL |
9.52mL |
|
3 |
0.1030M |
26.01mL |
35.09mL |
9.08mL |
a) Propose whether the unknown #4 is monoprotic or diprotic.
b) Propose the molar mass of the unknown #4.
c) show the calculation for the assumption for the monoprotic or diprotic.
In: Chemistry
Fe(III) forms a complex with thiocyanate, Fe(SCN)2+, that has a molar absorptivity of 7.00 x 103 at 580 nm. A 5.00 ml aliquot of a solution that contains 47.4 ppm Fe3+ is reacted with excess thiocyanate and diluted to 25 ml.
a) What fraction of 580 nm light is absorbed in a 1.00 cm pathlength cell by this solution?
Consider 5.00 ml of this solution diluted to a volume of 50ml
b) What fraction of 580 nm light is absorbed in a 1.00 cm pathlength cell by the diluted solution?
In: Chemistry
Calculate [OH−] for each solution.
A. pH = 2.52
B. pH = 8.09
C. pH = 13.58
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Write the formulas and provide the associated name for each formula for the four acids that contain oxyanions of bromine.
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Acetic acid and its conjugate base acetate can form an acid-base buffer. The pKa of acetic acid is 4.75. How much 10.0 M HNO3 must be added to 1.00 L of a buffer that is 0.0100 M acetic acid and 0.100 M sodium acetate to reduce the pH to 4.85 ?
In: Chemistry
*Please show how you got the calculations.
In a reactor scenario, 20.000 g Fe3O4 was reacted, at 1450 K, with NO having an initial pressure of 3.000 atm. At equilibrium, the mass of the solid-phase product (Fe2O3) was calculated to be 8.0742 g. 2Fe3O4(s) + 2NO(g) <=> 3Fe2O3(s) + N2O(g)
1. Calculate the mass of each gas-phase species at equilibrium.
2. Calculate the mass of Fe3O4 remaining at equilibrium from the mass of Fe2O3 calculated to exist at equilibrium.
3. Calculate the total mass of all species at equilibrium and prove that it equals the initial total mass of the reactants, to the .1 g place.
In: Chemistry
When electricity (the flow of electrons) is passed through a solution, it causes an oxidation-reduction (redox) reaction to occur. If the solution contains a metal cation such as Ag+, the flow of electrons will reduce the silver ion, causing solid silver to plate onto the electrode. The amount of metal plated depends on the number of electrons passed.
The total charge of a mole of electrons is 96,485 coulombs (C) and
1ampere(A)=1coulomb/second(C/s)
A) What mass of Cu(s) is electroplated by running 27.0 A of current through a Cu2+(aq) solution for 4.00 h?
B) How many minutes will it take to electroplate 34.1 g of gold by running 5.00 A of current through a solution of Au+(aq)?
In: Chemistry
AP CHEM question! Can you please follow these steps for each: 1.) net ionic equation, 2.) ice table, 3.) pH= pKa + log (CB/WA)
A 35.0 mL sample of 0.150 M acetic acid (HC2H3O2) is titrated
with 0.150 M NaOH solution. Calculate the pH after the following
volumes of base have been added:
A.) 0 mL
B.) 17.5 mL
C.) 34.5 mL
D.) 35.0 mL
E.) 35.5 mL
F.) 50.0 mL
In: Chemistry
For each of the reactions, calculate the mass (in grams) of the product formed when 3.75 g of the underlined reactant completely reacts. Assume that there is more than enough of the other reactant.
Ba(s)−−−−−+Cl2(g)→BaCl2(s)
CaO(s)−−−−−−+CO2(g)→CaCO3(s)
2Mg(s)−−−−−+O2(g)→2MgO(s)
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In the Introduction to Equilibrium experiment, what kind of errors would occur? (need to write discussion)
In: Chemistry
In time of flight mass spectrometers, ion separation is achieved using a(n)….. and why?
A. Field Free Drift Tube
B. RF only collision cell
C. Combination high-pass and low-pass filter
D. Magnetic Field
In: Chemistry
Research and then claim an application where solar or nuclear power is used. (Please try to keep the numbers even in that if you see mostly solar power applications selected, then go for a nuclear application, and vice-versa). For the application, you selected tell us about it and how it’s employed. Include any advantages or disadvantages for using it with respect to nuclear power. Finally, for the videos you watched, identify two of what you thought were the most important advantages of using each energy source to power say, a city of one million. Include a statement about your own opinion of which you’d like to be used in the future.
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The very useful restriction enzyme SpoBob hydrolyses the phosphodiester bond between the guanylates in the sequence AGGACCA. Is SpoBob generating blunt or sticky ends? Please explain.
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How does the Fluoride Ion-Selective Electrode it detect the fluoride ion? Include the species of fluoride that need to be considered, how to free the fluoride ion, and pH considerations.
In: Chemistry