For each reaction listed, determine its standard cell potential (in V) at 25°C and whether the reaction is spontaneous at standard conditions.
(a) 2 Au(s) + 3 Zn2+(aq) → 2 Au3+(aq) + 3 Zn(s)
(b) Co2+(aq) + Hg(l) → Co(s) + Hg2+(aq)
(c) Cu(s) + Fe(NO3)3(aq) → CuNO3(aq) + Fe(NO3)2(aq)
(d) Sn(NO3)2(aq) + Zn(s) → Sn(s) + Zn(NO3)2(aq)
In: Chemistry
A(aq) + B(aq) → 2C(aq)
If Kc = 3.4 x 10-17, this indicates that .....
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At equilibrium there will be nearly equal amounts of reactant and product. |
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At equilibrium there will be no product formed. |
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At equilibrium there will be considerably more product than reactant. |
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At equilibrium there will be considerably more reactant than product. Which of the following are true for all reactions that have achieved equilibrium?
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In: Chemistry
What mass of sucrose (C12H22O11) should be combined with 485 g of water to make a solution with an osmotic pressure of 8.00 atm at 280 K ? (Assume the density of the solution to be equal to the density of the solvent.)
In: Chemistry
Give one advantage and one disadvantage of using a plasma excitation source (as oppaosed to a flame) for emission spectroscopy.
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A student reacts 96g of salicylic acid with 10 mL of acetic anhydride producing 10.7g of acetyl salicylic acid. What is the percent yield of the reaction?
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A system initially contains 2 lb of liquid water at 110ºF and 0.4 lb of ice at 32 ºF. The system attains an equilibrium state, while pressure remains constant at 1 atm. For water, the specific enthalpy change for a phase change from solid to liquid at 1 atm is 144 Btu/lb. If heat transfer with the surroundings is negligible, determine
(a) the final temperature, in ºF
(b) the amount of entropy produced in the process, in Btu/ºR.
In: Chemistry
1. Explain how steps in a procedure remove impurities
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Which of the following substances has the lowest boiling point? C12H16 CH2Br2 Br2 ICl
How much energy in kJ will it take to melt 5.0 g of frozen Ar at -190o C?
T/F if methane was at -50o C it cannot be made to liquify at any pressure.
If H2O at -1.0o C and 1.0 atm has enough pressure applied to it, what phase change, if any, can occur?
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solid to liquid |
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liquid to solid |
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stays solid |
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stays liquid What is the concentration in percent by mass when a solution is prepared by dissolving 8.00 g of NaCl into 70.0 g of water? What kind of solute gets more soluble as the temperature of the solvent decreases? The normal vapor pressure of water at 30o C is 31.82 mmHg. When 25.0 g of glucose (C6H12O6) are dissolved in 25.0 g of water at 30o C, what is the solution's vapor pressure? What is the freezing point of a solution made up of 150.0 g of benzene (normal fp=5.5o C, Kf=5.12 oC/m) with 0.200 moles of naphthalene dissolved in them? |
In: Chemistry
Consider the following reaction between oxides of nitrogen: NO2(g)+N2O(g)?3NO(g)
1.
Calculate ?G? at 800 K, assuming that ?H? and ?S? do not change with temperature.
Express your answer using two significant figures.
2.Calculate ?G? at 1000 K.
In: Chemistry
If a solution containing 45 g of mercury(II) nitrate is allowed to react completely with a solution containing 14.334 g of sodium sulfate. a)How many grams of solid precipitate will be formed? b)How many grams of the reactant in excess will remain after the reaction?
In: Chemistry
Consider a 0.5 M solution of trimethylammonium chloride. The ion trimethylammonium is the conjugate acid of the the weak base trimethylamine.The pKb of trimethylamine is 4.2
A) Calculate [H+]
B) calculate the concentration of trimethylammonium ions
C) calculate the concentration of trimethylamine in equilibrium
D) calculate [OH-]
E) Calculate [Cl-]
F) Calculate the pH
In: Chemistry
A flask contains a gaseous mixture of 3.01mol of hydrogen and 5.84mol of oxygen gases. When these gases react, steam is produced.
a) Balance the equation for this reaction. H2(g) + O2(g) H2O(g)
b) What is the limiting reagent?
c) How many grams of steam are produced?
d) How many moles of limiting reagent remain unreacted? e) How many
moles of excess reagent remain unreacted?
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A flask with a sample of gas at room temperature and pressure weighs 97.4842 g. The same flask with air (density = 1.17 g/L) weighs 96.8848 g. The same flask filled with water (d = 0.998 g/mL) weighs 345.86 g. The pressure in the room is 0.989 atm and the temperature is 22.2 °C.
1. Calculate the volume of the flask.
2. Calculate the mass of the air that the flask can hold.
3. Calculate the mass of the empty (no air) flask.
4. Calculate the mass of the gas in the flask.
5. Use the Ideal gas law to calculate the moles of gas in the flask.
6. Calculate the molar mass of the gas in the flask.
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4. Calculate the pH of the following salt solutions (5 pts each). a. 0.237 M sodium cyanide, NaCN (aq) (HCN ka = 4.0 x 10-10) b. 0.166 M ammonium iodide, NH4I (aq) (NH4+ ka = 5.6 x 10-10)
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