1.921 g of the weak base trimethylamine, (CH₃)₃N (MW = 59.11g/mol) (K_b = 6.3 x 10^-5), is diluted in water to give 50.0 mL of solution. This solution is titrated with 0.10 M HCl. (assume all solutions at 25⁰C)

(a) What is the pH of the original amine solution?

(b) What is the pH of the solution after 162.5 ml of HCl is titrated?

(c) What is the pH after 325ml of HCl is titrated?

a. Calculate the moles of H2 produced from each trial

b. Vol of gas was not at standard temp and pressure. Convert the volume at the pressure and temperature of the experiment to a volume at standard temperature and pressure. (STP = 273. 15K, P = 1.00atm)

c. Using your answers from part a and b, calculate the molar volume of H2(g) (L/mol) at STP for each trial.

(For what ever reason, I am only able to put in a good value for mols of H2 into the computer, it keeps saying my calculations are incorrect for the rest. Trying to figure out what I am doing wrong)

h nmr for 2,4-Dimethoxybenzoicacid

Balance the equations or write the balanced chemical for the following:
A) C7H8O2(l) + O2(g) → CO2(g) + H2O(g)
B) Copper(II) hydroxide decomposes into copper(II) oxide and water when heated;
C) Solid calcium carbide, reacts with water to form an aqueous solution of calcium hydroxide and acetylene gas, C2H2.
D) As2O3(s) + NO3-(aq) → H3AsO4(aq) + N2O3(aq)

Calculate the equilibrium constant K of the reaction Sn(s)|Sn²⁺(aq)||Ag⁺(aq)|Ag(s) at 25 °C.

Consider the titration of 25.0 mL of 0.0500 M Sn2+ with 0.100 M Fe3+ in 1 M HCl to give Fe2+ and Sn4+, using a Pt and calomel electrodes. (a) write a balanced titration reaction (b) write two half-reactions fo the indicator electrode (c) write two Nerst equations for the cell voltage (d) calculate E at the following volumes of Fe3+: 1.0, 12.5, 24.0, 25.0, 26.0, and 30.0 mL. Sketch the titration curve.

When a 7.00-g sample of RbBr is dissolved in water in a calorimeter that has a total heat capacity of 3.090 kJ·K–1, the temperature decreases by 0.300 K. Calculate the molar heat of solution of RbBr.

What is percent yield fro your synthseis of octyl acetate (acetic anhydride and 1-octanol)? V of ctyl acetate is 1.53 mL.

3 mL of acetic anhydride and 2 mL 1-octanol. One drop of concentrated sulfuric acid.

A student dissolved 10.5 g of NH₄Cl in 40 mL of water.  The temperature of the water changed from 22.5^oC to 5.1^oC.  Calculate the enthalpy of hydration of ammonium chloride in J/mol.

1.  A student collected the data below while performing a kinetics experiment.

Use the above information to complete the following table (enter all answers with 3 significant figures)

Using the data from the previous problem, determine the order with respect to Substance A. Using the data from Problem 1, determine the order with respect to Substance B. Using the information from Trial 1 and the experimentally determined rate law, determine the value of the rate constant, k for this experiment. Report your answer with 3 significant figures.

Please answer all the questions and with the three significant digits after decimals. Please.

Preparing Buffer Solutions: Calculating the Number of Grams of Conjugate Base Needed

Use the table of K values given with this problem to choose the best weak acid to start from for making a buffer that holds the pH of the solution at 3.20. Make your selection so that you maximize the capacity of the buffer.
You select a 200.0 ml volumetric flask to which you add 54.00 mL of a 2.90 M solution of the weak acid you just selected. To finish preparing your buffer you must now add the sodium salt of the conjugate base. How many grams of the sodium salt of your conjugate base must you add so that when you finally fill the flask to the mark with deionized water the buffer will have a pH of 3.20.

I posted this question before and they got the answer of 8.00g which is NOT CORRECT, so I was looking someone else to help me with this.

In my lab we found OUR average molarity to be 0.83334 M, but we used 3% H2O2 (hydrogen peroxide), so I'm not sure how to do this or what numbers to even use.

7. Convert the average molarity of hydrogen peroxide into % (wt) of hydrogen peroxide (the density of the solution = 1.009g/ml).

8. Comparing the above calculated % of hydrogen peroxide with the known (labeled on the bottle) value, calculate the % experimental error.

The first four peaks in the X-ray powder diffraction pattern of sodalite are at 2 values of 9.97°, 14.12°, 17.32° and 20.02°. The radiation used for the experiment was Cu K with  = 1.5418 Å. Determine the lattice type and calculate the length, a, of the cubic unit-cell.

FeS can be roasted in O 2 to form FeO, according to the reaction 2FeS + 3O 2 2FeO + 2SO 2 If the slag (solid product) contains 80% FeO and 20% FeS , and the exit gas is 100% SO 2 , determine the extent of reaction and the initial moles of FeS. Use 100 lb as the basis. [0.557; 1.341 lb-mol]

A sample is analyzed to determine its iron content Fe2+ via a redox titration with potassium chromate as the titrant. In the titration Fe2+ is oxidized to Fe3+ and CrO4 2- is reduced to Cr 3+. What is the percent by mass of iron in the sample if 0.9087g of the sample required 45.68mL of a 0.04322 M K2CrO4 solution to reach the endpoint?

I worked out the balanced equation to be:

8H+ + 3Fe2+ + CrO4 2- = 3Fe3+ + Cr3+ + 4H2O

What is the mechanism by which solute is dissolved in non polar solvents? Explain briefly. (5 mark)