A buffer is prepared by adding 15.0 g of ammonium chloride (NH4Cl) to 5.00L of 0.200 M ammonia (kb=1.8x10^-5). 1. What is the pH of the buffer solution? (assume the addition of ammonia does not change the volume) 2. What is the pH of the buffer after 90.0 mL of 2.00M HCl are added to the original buffer?
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A 10.0 mL solution of 0.064 M AgNO3 was titrated with 0.032 M NaBr in the cell. S.C.E. || titration solution | Ag(s) Find the cell voltage for 0.5, 14.0, 20.0, and 32.0 mL of titrant. (The Ksp of AgBr = 5.0 ✕ 10−13.)
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Draw the two major allylic alcohol intermediates and the two final products in the following two-step synthesis. Show the correct stereochemistry of each compound; if applicable, use wedge/dash bonds to indicate chirality centers, and you must show hydrogens on these centers.
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You are asked to prepare 50 mL of a 2 g/L solution of CaCl2. you have a stock solution of 140 g/L. How many mL of the stock do you need to dilute to 50 mL to get this concentration?
If you mix 7 mL of a 340 g/L stock solution of KCl in a total volume of 1000mL, what is the KCl concentration in your solution? Answer in g/L.
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How many grams of water form when 4.80L of propane gas (C3H8) completely react?
How many grams of CO2 are produced from 18.2g of oxygen gas and excess propane?
How many grams of H2O can be produced from the reaction of 8.30
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2) In your own words, explain why it is necessary to select only one wavelength to pass through the sample (i.e. why don’t we just shine white light into the sample and measure the amount of light that passes through?) (5 points)
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Calculate the pH of the solution after the addition of the following amounts of 0.0577 M HNO3 to a 80.0 mL solution of 0.0750 M aziridine. The pKa of aziridinium is 8.04
a) 0.00 mL of HNO3 b) 7.72 mL of HNO3 c) Volume of HNO3 equal to half the equivalence point volume d) 99 mL of HNO3
e) Volume of HNO3 equal to the equivalence point f) 107 mL of HNO3
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Four ice cubes at exactly 0 ?C with a total mass of 52.5g are combined with 145g of water at 75?C in an insulated container. (?H?fus=6.02 kJ/mol, cwater=4.18J/g??C)
If no heat is lost to the surroundings, what is the final temperature of the mixture?
T=?
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Which metal hardening mechanism is reversible by annealing (heat treatment) of the material?
You are given an alpha-titanium alloy to process into a turbine blade. Based on the fact that the alloy has an HCP crystal structure, what general processing technique would you consider for the processing of the turbine blade? Explain your choice.
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You have 15.00 mL of a 0.100 M aqueous solution of the weak base C6H5NH2 (Kb = 4.00 x 10-10). This solution will be titrated with 0.100 M HCl.
(a) How many mL of acid must be added to reach the equivalence point?
(b) What is the pH of the solution before any acid is added?
(c) What is the pH of the solution after 5.00 mL of acid has been added?
(d) What is the pH of the solution at the equivalence point of the titration? (e) What is the pH of the solution when 20.00 mL of acid has been added?
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Calculate number of CO2 molcules in 2.30*10^-2 mole CO2.
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Balance the following redox reaction if it occurs in acidic solution. What are the coefficients in front of Zn and H+ in the balanced reaction?
Zn2+ (aq) + NH4+ (aq) ? Zn (s) + NO3
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The tetraethyl lead Pb(C2H5)4 in a 25.00 mL sample of aviation gasoline was shaken with 15.00 mL of 0.02263 M I2. (Hint: one mole of I2 reacts with one mole of the tetraethyl lead). After the reaction was complete, the unused I2 was titrated with 8.74 mL of 0.03949 M thiosulfate solution. Calculate the weight of Pb(C2H5)4 (MW = 323.4 g/mol) in each liter of gasoline.
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Caluclate the pH of a solution made by mixing 45.0mL of 0.25M HA (K a= 2.5x10 -5) with 15.0mL of 0.75M NaOH
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