You wash dishes for a chemistry laboratory to make extra money for laundry. You earn 12 dollars/hour, and each shift lasts 75 minutes. Your laundry requires 12 quarters/load.

Part A

How many shifts must you work if you wish to wash 10 loads of laundry?

Part B

How many loads of laundry can you wash if you work 3 shifts?

Part C

How many loads of laundry will each shift pay for if the cost per load rises to 16 quarters?

a 0.490 g sample of a compound is heated through the successive evolution of the following gases, all at 1.00atm pressure: 280 ml of h2o vapor at 182ºC, 112ml of ammonia vapor at 273ºC, 0.0225g ofwater at 400ºC and 0.200g of SO3 at 700ºC, At the end of the heating, 0.090 g of FeO remains. Deduce the empirical formula for the compound

A gas chromatogram of the organic components of a sample of beer using a column that separates compounds on the basis of their relative boiling points provides a GC trace with several peaks. Two of the smaller peaks, with retention times of 9.56 and 16.23 minutes, are believed to be ethyl acetate and ethyl butyrate, respectively.

a. From the above information, which component of the sample, ethyl acetate or ethyl butyrate, elutes faster? What are the reported boiling points of these two substances?

b. What GC experiment(s) could you perform to confirm the identity of the peaks at 9.56 and 16.23 minutes?

c. Suggest two ways in which you could adjust the conditions of the experiment so as to reduce the retention time for all components in the sample.

How much heat energy is required to convert 55.4 g of solid iron at 21 °C to liquid iron at 1538 °C? The molar heat of fusion of iron is 13.8 kJ/mol. Iron has a normal melting point of 1538 °C. The specific heat capacity of solid iron is 0.449 J/g·°C.

1.)A student prepares a potassium dichromate solution by dissolving .5263 gram of dry solid potassium dichromate in enough water to make 1000.mL of solution. What is the concentration of dichromate ions in the resulting solution?

2)A student measures 10.00 mL of an unknown solution of Fe2+ into an Erlenmeyer flask and dilutes with 90 mL of 1.0 M hydrochloric acid. She then titrates this sample with the solution prepared in question#1 .If 29.50 mL of the potassium dichromate solution is needed to reach the endpoint, what is the concentration of Fe2+ in the original unknown solution.

Basic chemical structures of the organisms Concept map

Please if someone going to answer please type, and if that's not possible please write legible thank you

A 360.0?mL buffer solution is 0.160M in HFand 0.160M in NaF.

What mass of NaOH could this buffer neutralize before the pH rises above 4.00?

If the same volume of the buffer was 0.370M in HF and 0.370M in NaF, what mass of NaOHcould be handled before the pH rises above 4.00?

Titration Curve of unknown Acid

Molarity of NaOH =.172

1. Your unknown acid is one of the following: oxalic acid (H2C2O4*2H20, pKa1=1.27, pKa2=4.27), citraconic acid (C5H6O4, pKa1=2.29, pKa2=6.15), or Maleic Acid (C4H4O4, pKa1=1.92, pKa2=6.09). These acids are classified as diprotic. Calculate the molar mass for your acid using the average mass from trials 1 and 2 and the average volume at the first equivalence point; then redo the calculation using the average mass from trials 1 and 2 and the average volume at the second equivalence point.

2. Using the average molar mass at the second equivalence point that you calculated in question 1, and your average values of pKa1 and pKa2, indentifiy your unknown acid. Explain.

Prepare a 2.00 L of a 2.00 M buffer of pH 4.35. You can use citric acid (pka 3.09, 192.1 g/mol) and NaOH (10.0 M). Calculate how much of each reagent (and water) to make the buffer (show work).

The answers are:

Citric acid: 786 g, NaOH: 514 mL, water: 1.486 L

How do you get to these results?

For 530.0 mL of a buffer solution that is 0.155 M in CH3CH2NH2 and 0.145 M in CH3CH2NH3Cl, calculate the initial pH and the final pH after adding 0.020 mol of HCl.

The combination of sodium chlorite and acetic acid forms hypochlorous acid (HOCl), which is the active ingredient in this reaction. Draw the arrow pushing mechanism of your reaction, using HOCl as reagent.

1. For the following, predict the products (if any). If there is no reaction, write “no rxn”. For the

questions where reaction occurs, write:

 balanced molecular equation

 balanced complete ionic equation

 balanced net ionic equation

 classify the reaction as either precipitation or acid base resulting in a gas

Include phases for all species.

a) NaI(aq) + Pb(ClO4)2(aq)

b) Ba(NO3)2(aq) + (NH4)2SO4(aq)

c) HCl(aq) + NaHSO3(aq)

d) Cu(CH3COO)2(aq) + Rb2CO3(aq)

e) aqueous potassium carbonate + hydrobromic acid

f) Mg(NO3)2(aq) + Zn(CH3COO)2(aq)

g) aqueous silver perchlorate + aqueous magnesium bromide

h) NH4Cl(aq) + KOH(aq)

A chemist is working with a formic acid � formate ion buffer system.

HCHO₂(aq) + H₂O(l) <=> CHO₂^-(aq) + H₃O⁺(aq) with K_a = 1.7�10^-4

One liter of the buffer contains 0.745 moles of formic acid and 0.385 moles of formate ion. What is the pH of the buffer? (Answer to 3 significant figures, no units.)

______________________________________________________

Solid sodium hydroxide (6.83 grams) is added to one liter of the formic acid � formate ion buffer described in the previous question. Assume the total volume has not changed significantly once the strong base has dissolved. What is the new pH of the buffer? (Answer to 3 significant figures, no units.)

What is the pH of the solution that results from micing 75 mL of 0.50 M NH₃(aq) and 75 mL of 0.50 HCL(aq) at 25 xC? (K_b for NH₃ = 1.8x 10^-5)

a. 0.60

b 2.67

c. 4.74

d. 4.93

e. 9.26

If 10.0 ml of 0.100 M strong base is titrated with 25.0 ml of 0.100 M strong acid, what is the pH of the resulting solution?