Consider the following reaction:

2 Al + 3 CuCl₂ → 3 Cu + 2 AlCl₃

The reaction begins with 83.16 g of Al and 49.19 g of copper II chloride.

How much of the excess reactant is left behind (unused)?  g

How many grams of Cu is produced:  g

How many grams of AlCl₃ is produced:  g

A solution is found to be 0.0404% by weight CoBr₃. What is the concentration of the Br^1- ion expressed in ppm?

Consider this reaction:

2CH₃OH(l) + 3O₂(g)₂O(l) + 2CO₂(g) H = –1452.8 kJ/mol

a.Is this reaction endothermic or exothermic?

b.H if the equation is multiplied throughout by 2?

c.H if the direction of the reaction is reversed so that the products become the reactants and vice versa?

What is the value of ∆H if water vapor instead of liquid water is formed as the product?

1.Draw a Lewis structure for each of them. Remember that some molecules violate the Octet Rule in different ways. Some of these use multiple bonds and some don't. You need to figure out which do. Use the rules we had in class for writing Lewis structures and compare with these with the molecules we did write Lewis structures for. None of these have resonance structures.

SF₆ CH₄ I₃^- N₂    XeF₄ NH₃ OH^- CO C₂H₄ (in this molecule there is no one central atom, the two carbons are bonded together and in addition each carbon bonds with two hydrogen atoms)

2.Draw a Lewis structure for each of the following. For two of these molecules there are resonance structures. See if you can identify which two they are and draw the resonance structures.

NF₃ NO₃^-   O₂ SO₂ NO⁺ PCl₃ F₂ HCl OF₂ IF

student is asked to standardize a solution of calcium hydroxide. He weighs out 0.993 g potassium hydrogen phthalate (KHC8H4O4, treat this as a monoprotic acid). It requires 20.1 mL of calcium hydroxide to reach the endpoint.

A What is the molarity of the calcium hydroxide solution?

This calcium hydroxide solution is then used to titrate an unknown solution of hydroiodic acid.

B. If 25.5 mL of the calcium hydroxide solution is required to neutralize 15.0 mL of hydroiodic acid, what is the molarity of the hydroiodic acid solution? M

Estimate the pH of a 25o C solution of both ammonium chloride, NH₄Cl, and acetic acid in water, at a concentration of 0.10 M, each.

How would Acetic Acid, HC2H3O2 and Sodium Acetate, NaC2H3O2 work as a buffer? Explain with equations.

Separation techniques were performed on a sample containing only sand and salt. The mass of the initial sample was 10.50 g. After the separation, 3.10 g of sand and 4.00 g of salt were recovered. What is the percent recovery of sand and salt?

1. What volume of 0.158 M HCl is required to neutralize 2.87 grams of Mg(OH)2?

2. Which ion(s) is/are spectator ions in the formation of a precipitate of BaSO4, when aqueous solutions of BaI2 and K2SO4 are mixed?

Ammonium bisulfide, NH4HS, forms ammonia, NH3, and hydrogen sulfide, H2S, through the reaction

NH4HS(s)?NH3(g)+H2S(g)

This reaction has a Kp value of 0.120 at 25 ?C. An empty 5.00-L flask is charged with 0.300g of pure H2S(g), at 25 ?C.

C) What are the partial pressures of NH3 and H2S at equilibrium, that is, what are the values of PNH3 and PH2S, respectively?

D) What is the mole fraction, x, of H2S in the gas mixture at equilibrium?

E) What is the minimum mass of NH4HS that must be added to the 5.00-L flask when charged with the 0.300g of pure H2S(g), at 25 ?C to achieve equilibrium?

Determine the pH for each of the following solutions:

a)A 300. mL solution of 18.4 mM HNO3

b)A 125 mL solution of 2.94 M cyclohexylamine

c)A 500. mL solution of 1.37×10–7 M Ca(OH)2

d)A 50.0 mL solution of 53.5 mM dilithium citrate

e)A mixture made with 50.00 mL of 74.2 mM 2,3-dimercaptopropanol,

and 20.00 mL of 209 mM potassium hydroxide

Calculate the pH of the following solutions: (a) 10-3 M HClO4 (note that for HClO4 the pKa = -7) (b) 10-3 M HOCl (note that for HOCl the pKa =7.52) (x) 10-6.5 M NaOH (d) 10-3 M NH4Cl (note that for NH4+ the pKa =9.25)

A 0.15 g sample of a purified protein is dissolved in water to 2.0ml of solution. The osmotic pressure is found to be 18.6 torr. Calculate the molar mass of the protein.

Consider the following reaction:
HC2H3O2(aq)+H2O(l)⇌H3O+(aq)+C2H3O−2(aq)
Kc=1.8×10−5 at 25∘C

If a solution initially contains 0.180 M HC2H3O2H, what is the equilibrium concentration of H3O+ at 25∘C∘C?