Iridium crystallizes in a face-centered cubic unit cell that has an edge length of 3.811 Å.

(a) Calculate the atomic radius of an iridium atom. (b) Calculate the density of iridium metal.

a 3.592 g sample of hydrated magnesium bromide, MgBr2. xH20, is dried in an oven. when the anhydrous salt is removed from the oven, it's mass is 2.263 g. what is the value of x?

Chemical Engineering problem.

The fresh feed to an ammonia synthesis plant contains 24.30% N 2 , 75.20% H 2 and 0.50%
Ar. The reaction in the reactor is not complete so that recycle is necessary. In a specific
operation, the fresh feed is mixed with recycled gases and the mixture is sent to the reactor.
The gases leaving the reactor are sent to a cooler-condenser from which pure liquid
ammonia is obtained. The gas stream from the cooler-condenser also includes some
ammonia in gaseous form, and is recycled to the reactor. The unlimited accumulation of
argon in the system is prevented by incorporating a purge stream into the recycle line. Some
additional, partial information about some of the process streams is given below:
Reactor Feed – Ammonia 26.56%
Purge – Nitrogen 9.79%, ammonia 31.27%
Calculate, on the basis of 100 moles of fresh feed
a) The moles of purge, liquid ammonia product and the recycle streams and the
composition of the purge stream.
b) The reactor and overall conversion amounts – both based on the limiting reactant.
c) The overall plant yield, expressed as the percentage of total reactants in the fresh
feed that is converted to product.

Describe “breakpoint chlorination” and why is it necessary?

Discuss thermal stratification, how it may cause a water quality issue that needs to be addressed and a treatment method to deal with the problem.

1)Write a balanced chemical equation for the reaction of gaseous nitrogen dioxide with hydrogen gas to form gaseous ammonia and liquid water.

Express your answer as a chemical equation. Identify all of the phases in your answer.

2)Write a molecular equation for the precipitation reaction (if any) that occurs when the following solutions are mixed. If no reaction occurs, write noreaction

Express your answer as a chemical equation. Enter noreaction if no precipitate is formed. Identify all of the phases in your answer.

a)sodium carbonate and lead(II) nitrate

b)potassium sulfate and lead(II) acetate

c)copper(II) nitrate and barium sulfide

d)calcium nitrate and sodium iodide

3) Identify the spectator ions in the following complete ionic equation.
Ba2+(aq)+2I−(aq)+2Na+(aq)+SO2−4(aq)→BaSO4(s)+2I−(aq)+2Na+(aq)

Express your answers as ions separated by a comma. Do not enter the coefficient or phases.

4)When a hydrochloric acid solution is combined with a potassium hydroxide solution, an acid-base reaction occurs.

Express your answer as a chemical equation. Identify all of the phases in your answer.

a)Write a balanced molecular equation for this reaction.

b)Write a net ionic equation for this reaction.

5)A solution contains an unknown amount of dissolved magnesium. Addition of 2.41×10⁻² mol of Na2CO3 causes complete precipitation of all of the magnesium.

a)What mass of magnesium was dissolved in the solution?

Use HSAB concepts to make predictions about which member of each pair should be more stable.

Explain your reasoning in each case.

(a) (PtCl4)2- or (PtF4)2-

(b) [Fe(H2O)6]3+ or [Fe(PH3)6]3+

(c) F3B:THF or Cl3B:THF

(d) (CH3)3B:PCl3 or (CH3)3B:P(CH3)3

(e) (CH3)3Al:pyridine or (CH3)3Ga:pyridine

Determine the bond orders of (a) S2, (b) Cl2, and (c) NO from their molecular orbital

configurations and compare the values with the bond orders determined from Lewis structures. (NO

has orbitals like those of O2)

Which of the following substances has polar covalent bonds?

Options are CH4, KBR, NH3, CaF2

What mass of ethylene glycol (C2H6O2) is required to lower the freezing point of 50.0 g of water by 10.0oC?

Mole fraction to molality. Convert 0.1538 mole fraction of propanol (C3H8O) in water to molality. (Hint: begin by assuming 1 mole total and determine the contributing moles of propanol and contributing moles of water.) Answer to 4 significant figures with appropriate units.

A. Calculate the concentrations of K1 and NO3 2 in an aqueous solution prepared by dissolving 30.3 g KNO3 in enough water to make 300. mL of solution.

B. Calculate the concentrations of Al13 and SO4 22 in an aqueous solution prepared by dissolving 17.1 g Al2 (SO4 ) 3 in enough water to make 400. mL of solution.

C. Calculate the concentrations of Na1 and SO4 22 in an aqueous solution prepared by dissolving 852 g Na2 SO4 in enough water to make 4.00 L of solution.

D. What mass (in g) of CaCl2 is needed to prepare 100. mL of an aqueous solution that is 0.25 M in Cl2?

E. If 100. mL of 18.0 M H2 SO4 solution are diluted to 10.0 L, what are the concentrations of H1 and SO4 22 in the diluted solution?

To prepare a solution of NaBr, you weigh out 2.639 (±0.003) g and dissolve it to specification in a volumetric flask whose volume is 100.00 (±0.08) mL. Express the molarity of the solution, along with its uncertainty, with an appropriate number of digits.

The chemical industry is enormous in the industrialized world. How has society benefitted from advances in the chemical industry? What negative effects has the growth of the chemical industry had on society?