Mass of flask and foil (g) = 63.4842 Mass of flask, foil, and condesned vapor (g) = 63.6995 Temperature of boiling water bath (C) = 95 degrees C Volume of flask (mL) = 134 Barometric pressre (mmHg) = 763.8 Room temperature (C) = 21.0 degrees C Vapor pressure at room temperature (mmHg) = 100 Find the following: 1) Uncorrected mass of condensed vapor (g) = ? 2). Corrected density of air (g/L) = ? 3). Average volume of flask (L) = ? 4). Initial mass of air in flask (g) = ? 5) Final partial pressure of air in flask (mmHg) = ? 6). Final mass of air in flask (g) = ? 7). Mass of air lost (g) = ? 8). Corrected mass of condensed vapor (g) = ? 9) Molecular weight (g/mol) = ?

How many minutes will it take to plate out 16.22 g of aluminum metal from a solution of Al³⁺ using a current of 12.9 amps in an electrolytic cell?

At 1 atm, how much energy is required to heat 85.0 g of H2O(s) at –24.0 °C to H2O(g) at 135.0 °C? Helpful constants can be found here.

Calculate the pH of the solution after the addition of the following amounts of 0.0649 M HNO3 to a 70.0 mL solution of 0.0750 M aziridine. The pKa of aziridinium is 8.04.

a) 0.00 mL of HNO3

b) 7.30 mL of HNO3

c) Volume of HNO3 equal to half the quivalence point volume

d) 77.5 mL of HNO3

e) Volume of HNO3 equal to the equivalence point

f) 85.8 mL of HNO3

Please answer all parts of the question detailed with work. I will know if you are wrong, so please answer to the best of your ability.

Hint:

Aziridine (C2H5N), a weak base, reacts with a strong acid such as HNO3 to form its conjugate acid aziridinium (C2H5NH ). A strong acid reacts completely with a stoichiometric amount of weak base after each addition of the strong acid. In the titration of a weak base with a strong acid, there are four regions of the titration curve that require different calculations when determining the pH of the solution. 1) Before any strong acid is added to the solution. 2) Between the initial addition and the equivalence point. 3) At the equivalence point. 4) After the equivalence point.

The bond angle in NH₃ is significantly smaller than the ideal bond angle of 109.5° because of the lone pair on the central atom. Which best explains why the bond angle in SO₂ is very close to 120° despite there being a lone pair on the central atom?

Chemical equations serve a variety of purposes, but the most general form of a chemical equation is reactants -> products. Most often, reactants and products are described by their chemical formula, possibly including a designation of state of matter. Contrary to a general chemical equation, a balanced chemical equation always uses molecular formulas and is amended by stoichiometric factors to assure conservation of mass and/or moles.

Chemical equations represent chemical reactions, and chemical reactions can be classified according to two groups:

Group I (bond breakage and/or bond formation): The four reaction types are Synthesis, Decomposition, Single Displacement, Double Displacement.

Group II (common reaction principles): Representative examples are Precipitation, Redox, Acid-Base, Combustion. Choose from the following general chemical equations, and illustrate the four principle group I reaction types, and the four representative group II reaction types:

A) aqueous potassium sulfate + aqueous barium nitrate -> aqueous potassium nitrate + solid barium sulfate

B) magnesium metal + nitrogen gas -> solid magnesium nitride

C) copper metal + aqueous silver nitrate -> aqueous copper nitrate + silver metal

D) chlorine gas + fluorine gas -> chlorine monofluoride gas

E) aqueous hydrochloric acid + aqueous calcium hydroxide -> aqueous calcium chloride + water

F) gaseous sulfur dioxide + oxygen gas -> gaseous sulfur trioxide

G) solid calcium carbonate -> solid calcium oxide + gaseous carbon dioxide

H) solid silver oxide -> oxygen gas + silver metal

When you discuss reaction types, formulate the chosen general equation as balanced chemical equation.

Any given equation might serve as an example for a group I as well as for a group II reaction, but try to use as many different equations as possible.

a rock returned from the surface of the moon has a ratio of Rb⁸⁷ to stable Sr⁸⁷ atomos equal to 14.45 assuming that this was all Rb⁸⁷ upon the formation of the solar system, estimate the age of the solar system.

ans key:

t= 4.537*10^{9 yr}

11. If 0.0296 L of stock solution are diluted to 3.00L to form 0.345 M solution, what is the concentration of the stock solution?

56.0 mL of 2.50 M Fe(NO₃)₂ is combined with 25.0 mL of 0.0525 M Na₂CO₃.

K_sp of FeCO₃ is 2.1 × 10^-11.

What mass of FeCO₃(s) will be produced? in grams

What is the [Fe²⁺] in the solution final solution? in M

What is the [CO₃^2-] in the solution final solution? in M

An alkane with the formula C6H14 can be prepared by hydrogenation of either of only two precursor alkenes having the formula C6H12. Write the structure of this alkane, give its IUPAC name, and show the reactions. My confusion is to why the answer is not simply 2,3-hexene and the alkane is not hexane.

Find the temperature in ºC at which Kp = 43.7 for the reaction H2(g) + I2(g) ⇌ 2 HI(g). Use ∆Hºrxn and ∆Sºrxn to calculate and assume that they are independent of temperature. Use the thermodynamic data in the appendix of your textbook; I have provided the needed appendix on BlackBoard for your convenience. Report your answer to zero places past the decimal.

Nuclear Binding Energy

a)Calculate the mass defect of the helium nucleus 52He. The mass of neutral 52He is given by MHe=5.012225amu. Express your answer in atomic mass units to four significant figures.

b)Calculate the binding energy E of the helium nucleus 52He (1eV=1.602×10−19J). Express your answer in millions of electron volts to four significant figures.

c)Calculate the binding energy per nucleon of the helium nucleus 52He. Express your answer in millions of electron volts to four significant figures.

Using a molecular mechanics program, calculate the energy difference or the difference in heats of formation between Z- and E-stilbene. How do your computed values compare to the difference in heats of hydrogenation of the two isomers.