An element crystallizes in a body-centered cubic lattice. The edge of the unit cell is 3.28 Å in length, and the density of the crystal is 6.50 g/cm3 .

a.) Calculate the atomic weight of the element.

Balance each of the following reations using the half reaction method. Show all work

a. Bi(OH)₃(S) + Sn(OH)₃^-(aq) ---> Sn(OH)₆^2- (aq) + Bi(s) (Basic solution)

b. BrO₃^-(aq) + Sb³⁺(aq) ---> Br ^- (aq) + Sb⁵⁺ (aq) (acidic solution)

Thank you for your help!

1) Zinc reacts with hydrochloric acid according to the reaction equation.How many milliliters of 4.00 M HCl(aq) are required to react with 5.85 g of an ore containing 44.0% Zn(s) by mass?

2) The amount of I3–(aq) in a solution can be determined by titration with a solution containing a known concentration of S2O32–(aq) (thiosulfate ion). The determination is based on the net ionic equation.

2SO2O3(2-)(aq) +I3(-)(aq) --->>> S4O6(2-)(aq) + 3I(-)(aq)

Given that it requires 25.6 mL of 0.460 M Na2S2O3(aq) to titrate a 10.0-mL sample of I3–(aq), calculate the molarity of I3–(aq) in the solution.

Pressurized tanks are commonly used in gas propulsion for space applications. Two rigid, insulated tanks are interconnected by a valve. Initially 0.79 kmol of nitrogen at 200 kPa and -18oC fills one tank. The other tank contains 0.21 kmol of oxygen at 100 kPa and 27oC. The valve is opened and the gases are allowed to mix until a final equilibrium state is attained. During this process, there are no heat or work interactions between the tank contents and the surroundings. Determine the following:

a. The volume of each gas

b. The final temperature of the mixture

c. The final pressure of the mixture

d. The amount of entropy produced in the mixing process

Heavy metal azides, which are salts of hydrazoic acid, HN3, are used as explosive detonators. A solution of 0.20M hydrazoic acid has a pH of 3.21. What is the Ka for hydrazoic acid?

You find two bottles of white solid on a shelf in the stock room without labels. You then find two labels CaCl2 (s) and KCl (s0 lyring right beside. You want to determine which is which. The solids can be differentiated by dissolving each solid in water and measuring the change in temperature.

delta H(f) CaCl2 (s) = -796 kJ/mol     

delta H(f) KCl (s) = -437 kJ/mol         

You dissolve 0.100 moles of unknown A in enough water to make a 200g solution at 22 degress C. The final temperature of the system is 31.7 degress C. Which solid is unknown A?         

What would be the expected Final Temperature if you dissolved 0.100 moles of unknown B in enough water to make a 200g solution at 22 degrees C?                  

Draw an enthalpy diagram for the dissolution of unknown B, be sure to include reactants, products, enthalpy, delta H, reaction progress.

Given that ΔG∘ = −13.6 kJ/mol, calculate ΔG at 25∘C for the following sets of conditions.

1) 30 atm NH3, 30 atm CO2, 4.0 M NH2CONH2 Express the free energy in kilojoules per mole to two significant figures.

2) 8.0×10−2 atm NH3, 8.0×10−2 atm CO2, 1.0 M NH2CONH2 Express the free energy in kilojoules per mole to two significant figures.

Is the reaction spontaneous for the conditions in Part A and/or Part B?

A) Is the reaction spontaneous for the conditions in Part A and/or Part B?

B) spontaneous for the conditions in both parts.

C) spontaneous for the conditions in Part but nonspontaneous for the conditions in Part B. spontaneous for the conditions in Part B but nonspontaneous for the conditions in Part A

D) nonspontaneous for the conditions in both parts.

For the production of ammonia from its elements, 3H2(g)+N2(g)→2NH3(g),
ΔH = -21.9 kcal.

Part A: Is this process endothermic or exothermic?   

Part B: How many kilocalories are involved in the production of 27.75 g of NH3?

Part C: How many kilocalories are involved if 26.90 g of H2 are consumed in this reaction?

What are the 4 major macromolecules and how to they support life.Be sure to check your spelling. Minimum response should be 10 sentences.

a)How many mol are in 64.61 g of nickel(II) phosphite?

b)How many mol of carbon are in 30.6 g of aluminum carbonate?

c)What is the mass (in grams) of 1.01 mol of iron(III) chloride?

d)What is the mass of oxygen in 5.71 g of aluminum oxide?

what new facts you discover about the nature of matter and/or what surprise you in the experiment called the molecular models: lewis dot formula, VSEPR theory, and valence bond theory

if youre doing an analysis with a tlc plate and you use ethyl actete (polar) as the solvent please rank the distance that these molecules would move (aka which one would be the highest on the plate). They are the same molecule, the only thing that changes is the functional group. One has an alcohol functional group, one has a ketone, and the other has alkene functional group

If the Ksp of PbI₂ is 7.1 X 10^-9, will precipitation occur when 10 mL of 1.0 X 10^-4 M Pb(NO₃)₂ is mixed with 10 mL of 1.0X10^-3 M KI?

Will precipitation occur when 10mL of 1.0X 10^-2 M Pb(NO₃)₂ added to 10mL of 2.0 X 10^-2 M KI?

*Please show step-by-step, as I am really lost. Thank you in advance.

a) Which electrons experience a greater Z_eff (effective nuclear charge): the valence electrons in Be or the valence electrons of N? Why?

Using the simple equation on page 260, calculate the Z_eff of 3p electron of K atom.

a. Using the trends in ionization energy of sodium and electron affinity of oxygen, explain why sodium oxide has the formula Na₂O and not NaO.

Which specific orbital loses an electron in the fourth ionization step of Carbon?

2) Write the atomic radii and ionic radii of the following using the interactive Periodic   
Table on the web (Link: http://www.chemeddl.org/resources/ptl/index.php).

a-    Explain the trend in the radii for two elements in the same group and that for two      
     elements in the same period. Be sure to include units.

                                                Atomic Radius                                   Ionic Radius

            a. Ra             

        b. Cd

    c. Sr

4)Briefly explain why valence electrons are more important than core electrons in determining the reactivity and bonding in atoms.

Write the abbreviated electron configuration for the following pairs:

   a-Ir (Iridium) atom
   b- Ir³⁺      
   c- Se atom
d- Se^2—

How many unpaired electrons are there in the following: ( you should do their condensed electron configurations first)

a-Fe atom

b-Cu¹⁺ ion