Calculate the change in pH when 9.00 mL of 0.100 M HCl(aq) is
added to 100.0 mL of a buffer solution that is 0.100 M in NH3(aq)
and 0.100 M in NH4Cl(aq). A list of ionization constants can be
found here. Calculate the change in pH when 9mL of .1M NaOH is
added to the original buffer solution
In: Chemistry
Enough of a monoprotic acid is dissolved in water to produce a 0.0175 M solution. The pH of the resulting solution is 2.35. Calculate the Ka for the acid.
In: Chemistry
A. If the Mg3N2 is not decomposed, will the reported magnesium to oxygen ratio be high or low? Explain. Hint: The Mg:N mass ratio is 1:0.38 and the Mg:O mass ratio is 1:0.66.
B. An analysis shows that 2.97 g of iron metal combines with oxygen to form 4.25 g of an oxide of iron. What is the empirical formula of the compound?
In: Chemistry
In a 0.5 M solution of a diprotic acid H2A (Ka1 -3.6 x 10-5 and Ka2 - 8 x 10-12 at 25*C) What is the equilirbium concnetration of A2-?
In: Chemistry
a) If a molecule can hydrogen bond, does it guarantee that it will have a higher boiling point than a molecule that cannot? Explain why not
b) If a molecule has a stronger dipole moment than another molecule, does it guarantee it will have a higher boiling point? Explain why not
In: Chemistry
The following factors must be taken into consideration when proposing a mechanism for a nucleophilic substitution reaction. Select all that apply.
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nucleophilic |
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the overall thermodynamics of the reaction |
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basicity |
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the solvent |
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the structure of the substrate |
In: Chemistry
Write Lewis structure that obeys the octet rule for BrO−3 and assign formal charges to each atom.
In: Chemistry
During the titration of a particular acid, the PH changes from 7.0 to 9.0 with the addition of 0.01mL of base. An indicator was used that had KI= 1.0x10-8. Calculate the ratio of basic to acidic forms of the indicators before and after the last 0.01mL of base was added. Use the result of your calculation to explain why this would or would not be a good indicator for this titration compared to phenolpthhalein.
a. I got PH change, then need to multply by 0.01ml of base. But why? What is that number called?
b. Need to calculate ratio of basic to acidic forms of the indicator before and after the last 0.01ml of base was added. I need precise steps of calculation with explainations.
c. How can I use my calculation to explain that the indicator used is good or bad for the experiment? Pleas explain.
In: Chemistry
When the following reaction is balanced what is the coefficient for -OH? ____N2H4 + ____ClO3- + ____-OH ----> ____NO3- + ____Cl- + ____H2O
(Please explain method step by step, this is a redox reaction)
In: Chemistry
The vibrational energy levels of NaI lie at the following wavenumbers: 142.81,427.31, 710.31, 991.81 cm-1.
Show that they fit an expression ?e(v +
In: Chemistry
A combustion gas has the following composition (by volume): 75%
N2, 5.5% O2, 11% CO2,
8.4% H2O, and 0.1% CO.
a. What is the CO concentration in mg/dscm (dry standard cubic
meter)?
b. What is the average molecular weight of the gas?
c. What is the density of the gas at T = 350 °F and P = 755
mmHg?
d. If the measured flowrate was 1000 L/s at the temperature and
pressure stated in
part (c), what would the volumetric flowrate be at STP?
In: Chemistry
Calculate the concentration of H+ in a 0.250 M solution of oxalic acid. Consider only [H+] from the first ionization. (Ka = 5.37 x 10^-2) Then calculate [H+] of the same solution, including the H+ ions resulting from the second ionization. (Ka = 5.37 x 10^-5)
In: Chemistry
A solution contains 2.2x10^-3 M Cu2+ and 0.33 M LiCN. If the Kf for Cu(CN)4^2- is 1.0x10^25, how much copper ion remains at equilibrium?
In: Chemistry
Which of the following acids would be most suitable for preparing a buffer of pH 3.10 and why: hydrogen peroxide (pKa= 11.65), propanoic acid (pKa=4.874), cyanoacetic acid (pKa= 2.472), and 4-aminobenzenesulfonic acid (pKa=3.232)?
In: Chemistry