5.0 g of iron is reacted with 5.0g of water according to the chemical equation shown below. 3 Fe(s) + 4 H2O(l) → Fe3O4(s) + 4 H2(g)

a) Calculate the amount of Fe3O4 produced, in grams.

b) What is the mass of excess reagent, in grams?

1. Write out the balanced equation for the oxidation of hydrobromic acid by hydrogen peroxide.
2. How many stereoisomers of stilbene dibromide can exist?
3. A possible definition of a meso compound is: “while possessing 2 or more assignable
stereocenters, a meso compound is superimposable (identical to) its mirror image in at least
one conformation”. In other words, it is identical to its would-be enantiomer except for the fact
that the molecule contains… what? What physical characteristic arises in meso compounds
that results in the above definition?
4. Let us assume a cut-and-dry, black-and-white case that the mechanism does only one of 2
things when each molecule of product is produced: (1) goes entirely bromonium-ion/antiaddition;
or (2) goes through a fully-fledged planar carbocation intermediate with absolutely
no selectivity.
a. If you were to find by quantitative analysis that exactly 50% of your product mixture
was the meso stilbene dibromide and the other 50% was racemic stilbene dibromide,
then is mechanism case (1) or (2) favored? If so, qualitatively, by how much?
b. Think again. Question (a) is a mind-bender. I want to know what you originally /
immediately thought, and what you eventually came to. If they are not different, you
are either a genius or need to think more. Write out all the possibilities…
c. If you find, qualitatively, that >95% of the product is meso, what does this imply about
the mechanism? What percent of the time does the mechanism go by scenario (1)…
greater than what number?
5. Describe a more likely blend of mechanisms that could have produced your estimated product
distribution

Nevermind

A 1.0 oz (30.0 mL, 1.00 g/mL) espresso contains 55.0 mg of caffeine (C8H10N4O2). Calculate the caffeine concentration in the following units. You may assume your espresso contains only caffeine and water for simplicity.

a. ppm

b. %w/w

c. ppb

d. Molarity

e. molality

f. Xcaffeine (mole fraction)

What is the prefix for a -SH group?

Use the Henderson–Hasselbalch equation to calculate the pH of each solution:

a solution that is 17.0 g of HF and 26.5 g of NaF in 125 mL of solution

PLEASE SHOW ME YOUR WORK

A 20 gram iron block at an initial temperature of 20oC is placed in 20 grams of water at an initial temperature of 80oC. Assuming no heat is lost to the surroundings, what would be the final temperature of the system once you reach thermal equilibrium?

CSiron=0.449JgoC

CSwater=4.18JgoC

74.2o C

80.0o C

25.8o C

50.0o C

112o C

To what volume (in mL) should you dilute 100.0 mL of a 5.00 M CaC2 solution to obtain a 0.750 M CaC2 solution?

The oxidation of copper(I) oxide, Cu2O(s), to copper(II) oxide, CuO(s), is an exothermic process.

2Cu2O + O2 = 4CuO

The change in enthalpy upon reaction of 85.49 g of Cu2O(s) is -87.23 kJ. Calculate the work, w, and energy change, ΔUrxn, when 85.49 g of Cu2O(s) is oxidized at a constant pressure of 1.00 bar and a constant temperature of 25 °C.

Answer in Kg.

Start by converting the mass of Cu2O that reacts (85.49 g) to the number of moles of O2 gas consumed in the reaction. Then use the ideal gas law to determine the change in volume (ΔV) during this reaction process, where Δngas is the actual amount of gas consumed. Values for R can be found at this link.

how many carbon dioxide molecules are produced for every gram of ethanol combusted?

Sodium burns in chlorine to form sodium chloride, NaCl. How many grams of sodium Chloride will be formed when 1.8 grams of sodium is burned in 2.00 grams of Chlorine? what is the excess reactant in this reaction? what is the limiting reactant? how much excess reactant remains unreacted?

1. How can the K_c of two possible reactions be compared to determine which reaction is occuring?

2. How are the equilibrium moles of reactants(ions remaining in solution) calculated?

3. What are the equilibrium constant equations for the below reactions?

Fe³⁺ + SCN^- <==> FeSCN²⁺

Fe³⁺ + 2SCN^- <==> Fe(SCN)₂+

4. How are initial moles of a reactant calculated?

5. How is the concentration of the product determined for a reaction?