Problems & Step-by-Step Video Solutions

A certain element X and oxygen form four different binary compounds.  These compounds have the following compositions:

(a) Show that the law of multiple proportions holds for these compounds.

(a) When they form ionic compounds, which elements in the 3^rd row of the periodic table are expected to lose electrons? Which ones should gain electrons?

(a) Provide systematic names of the following compounds: AlCl₃ , FeSO₃, N₂O₅.

(a) Calculate the molar mass of calcium phosphate, Ca₃(PO₄)₂.

(a) A certain compound has the following mass composition: 5.15% hydrogen, 49.48% carbon, 28.87% nitrogen and 16.49% oxygen. Determine its empirical formula.

Balance the following reactions:

(a) NH₃ + O₂ → NO + H₂O

(b) The compound C₈H₁₀N₄O₂ is burned in oxygen to produce CO₂, H₂O and N₂.

Metallic lead can be produced from lead (IV) oxide according to the following reaction:

PbO₂(s) + 2CO(g) → Pb(s) + 2CO₂(g)

For the following reaction:

Fe(s) + 2 Cr(s) + 4 CO(g) → FeCr₂O₄(s) + 4 C(s)

Calculate the final chloride ion concentration in the following:

(a) 25.64 mL of 1.35 M calcium chloride diluted to a final volume of 214.0 mL.

68.5 mL of 0.430 M potassium sulfate is mixed with 56.3 mL of 0.550 M barium nitrate.

(a) What is the precipitate?

(b) Write down the net ionic equation.

(c) Calculate the mass of the precipitate produced?

(a) Determine the oxidation state of all elements in the following (unbalanced) reaction: HNO₃(aq) + Fe(s) → NO(g) + FeNO₃(aq)

Balance the following redox equation:

(a) Balance the following redox equation in acidic solution:

(a) Balance the following redox equation in acidic solution:

C₂H₅OH (aq) + MnO₄^- (aq) → MnO₂ (s) + CO₂ (g)

A gas starts at 742. torr and 25.0 ^oC with an initial volume of 3.27 L.

(a) It is first heated to 65.5 ^oC at constant pressure. Calculate its new volume.

(a) Calculate the root mean square velocities of O₂ and H₂ gas at room temperature.

When a 4.25-g sample of solid ammonium nitrate dissolves in 60.0 g of water in a coffee-cup calorimeter, the temperature decreases from 22.06 ^oC to 16.9 ^oC.  Calculate DH (in kJ/mol NH₄OH) for the solution process:

NH₄OH (s) → NH₄⁺ (aq) + OH^- (aq)

Given the following data:

N₂ (g) + O₂ (g) → 2 NO (g) DH = +180.7 kJ

2 NO (g) + O₂ (g) → 2 NO₂ (g) DH = -113.1 kJ

2 N₂O (g) → 2 N₂ (g) + O₂ (g) DH = -163.2 kJ

calculate DH for the reaction:

Lasers can be made with different materials.

(a) CO₂ lasers produce light with a 10.6 micron wavelength. What is the frequency of this light? Is it in the visible, IR, or UV?

What is the de Broglie wavelength of an electron traveling at 1% the speed of light?

Of the atoms P, S, Ar, Se, Sb and Sn:

(a) which one has the smallest size?

(b) which one has the lowest ionization energy?

For the reaction:

2 N₂O₅(g) --> 4 NO₂(g) + O₂(g)

(a) How is the rate of appearance of NO₂ (d[NO₂]/dt) related to the rate of disappearance of N₂O₅ and the rate of appearance of O₂?

For the reaction:

A + 2 B + 4 C --> products

(a) Use the following initial rate data to determine the rate law.

For the reaction:

     B(g) --> products

a certain amount of B was placed in a sealed container and allowed to react.

(a) The following concentration data were obtained at different times.

What is the order of the reaction in B?

(b) What is the value of the rate constant?

(a) Write down the overall reaction for the following mechanism:

    NO₂(g) + F₂(g) --> NO₂F + F (fast equilibrium)

    F + NO₂ --> NO₂F (slow)

(b) Which species is (are) the intermediates? Is any species acting as a catalyst?

(a) A certain chemical reactions is twice as fast at 60 ^oC compared to 30 ^oC, calculate the activation energy of this reaction.

(a) Write down the equilibrium expression for the following reaction:

2 N₂O₅(g) --> 4 NO₂(g) + O₂(g)

(b) If the equilibrium constant K_p for this reaction is 0.00352 at 330 K, what is the value of the equilibrium constant K_c at this temperature?

For the reaction:

H₂(g) + F₂(g) --> 2HF(g)

the equilibrium constant is 12.1.

(a) If initially 0.500 mole of H₂, 0.300 mole of F₂ and 1.000 mole of HF were mixed in a 1.50-L flask, which way will the reaction move to reach equilibrium?

The equilibrium constant for the reaction:

2 N₂O₅(g) --> 4 NO₂(g) + O₂(g)

For the following reaction:

UO₂(s) + 4HF(g) <=> UF₄(g) + 2H₂O(l)        DH = +23.2 kJ/mol

how will the following changes affect the equilibrium?

Using the table of K_a values, order the following bases by their relative strength:

(a) What is the H₃O⁺ and OH^- concentration in a pH 4.550 buffer solution?

(a) Calculate the pH of a 0.0475 M solution of HNO₂.

(a) Calculate the pH of a solution containing 0.0475 M HNO₂ and 0.100 M NH₄Cl.

The K_a of a certain monoprotic acid HX is 3.87 x 10^-6.

(a) Calculate the K_b of its conjugate base X^-.

Calculate the concentrations of all dissolved species in a 1.00 M solution of oxalic acid.

(a) How much NaOH has to be dissolved in 500. mL of 0.400 M acetic acid to form a pH = 4.500 buffer?

(b) If HCl gas is dissolved in this buffer, how will the pH change?

50.00 mL of a 0.100 M solution of methyl amine (CH₃NH₂) is titrated with 0.150 M HNO₃.

(a) Calculate the volume of HNO₃ needed to reach the equivalence point.

(b) Calculate the pH at the equivalence point.

(c) Calculate the pH after 10.0 mL of HNO₃ has been added.

60.0 mL of a weak monoprotic acid of an unknown concentration is titrated with 0.100 M NaOH. 86.3 mL of NaOH is needed to reach the equivalence point.

(a) What is the concentration of the weak acid?

(b) The pH at the half-equivalence point is 5.87. Calculate the K_a of this unknown acid?

The K_sp for CaF₂ is 4.0 x 10^-11.

(a) Calculate the solubility of CaF₂ in pure water.

(b) Calculate the solubility of CaF₂ in a 0.100 M KF solution.

(a) Calculate the boiling point of methyl alcohol (CH₃OH).

For the reaction:

2SO₂(g) + O₂(g) --> 2SO₃(g)

(a) Calculate DH⁰, DS⁰, and DG⁰ .

(b) Explain the sign of DS⁰.

(c) Is this reaction spontaneous at standard condition?

(d) Calculate the equilibrium constant of this reaction at 298 K.

(e) Calculate the equilibrium constant of this reaction at 1000 K.

(a) Calculate the boiling point of methyl alcohol (CH₃OH).

Consider the following (at standard conditions):

Na⁺, Cl^-, Ag⁺, Ag, Zn²⁺, Zn, Pb, Fe, Fe²⁺, Mg, Mg²⁺, Sn

(a) Which ones can act as oxidizing agents? Which one is the strongest oxidizing agent?

(b) Out of the list in (a), which species can be reduced by Al?

(c) Which ones can act as reducing agents? Which one is the strongest reducing agent?

A galvanic cell is based on the following redox reaction:

Zn + Cu²⁺ --> products

(a) Write down the products of this reaction.

(b) Calculate the standard cell potential.

(c) Make a sketch of this cell and label all the relevant parts.

(d) Calculate the cell potential if everything is at standard condition except for [Cu²⁺] = 1.00 x 10^-4 M.

A concentration cell is constructed using two Ag/Ag⁺ half-cells with the same volume.

(a) The concentration of Ag⁺ in one cell is 1.00 M and 0.100 M in the other. Calculate the cell potential.

(b) When the reaction proceeds, what happens to the concentrations in the two half-cells?

(c) Which side is the cathode?

Use the following standard reduction potentials to calculate the K_sp of mercury (I) chloride.

Hg₂Cl₂ + 2e^- --> 2Hg + 2Cl^-       +0.34 V

Give systematic names for the following compounds:

(a) [Co(NH₃)₅Cl]Cl₂

(b) K₃[Fe(CN)₆]

(c) [Fe(en)₂(NO₂)₂]₂SO₄

Provide chemical formula for the following:

(a) tetracarbonyldifluoroiron (III) nitrate

Draw all distinct isomers of the following complexes:(a) [Co(en)₃]²⁺

Explain the following observations by using the crystal field theory and the proper electronic configurations of the d-orbitals in these complexes:

(a) Fe(CN)₆^4- is diamagnetic but Fe(H₂O)₆²⁺ is paramagnetic.

(a) ²¹⁰Po undergoes an a-particle decay. What nuclide does this produce?

(a) Calculate the nuclear binding energy per nucleon for the ⁷⁹Kr nuclide (the atomic mass of ⁷⁹Kr is 78.920083 amu).