ZnCl2 (aq) + Al (s) ---- Zn(s) + AlCl3 (aq)

[Al3+] = 0.8 M    [Zn2+] = 1.3M

Zn2+(aq) +2e- ---Zn(s)    -0.76V

Al3+(aq) + 3e- --- Al (s)    -1.66V

Balance the equation above.

Give the equation for the reaction quotient(Q) and solve for it. Are there units for (Q)?

Solve for the standard potential for the cell (EO cell) at 295K. First give equation.

Solve the Nernst equation for this cell at 295K.

A student researcher performed a chromatographic separation of caffeine and aspartame with methanol as the mobile phase using a C–18 column. The retention times for methanol (tm) , caffeine (tc) , and aspartame (ta) were 41.8 s , 96.3 s , and 143.8 s , respectively.

What is the selectivity factor (relative retention), α , for this column?

α=

Calculate the hypothetical retention times for caffeine and aspartame if their retention factors were reduced by 28.0% . Assume the mobile phase retention time (tm=41.8 s) remains constant.

tcaffeine=

staspartame=

Select the statements that correctly describe the outcome if the partition coefficient for caffeine (Kc) were to decrease.

The retention time of caffeine would increase.

The retention time of caffeine would decrease.

Caffeine would spend a greater amount of time in the mobile phase.

The retention factor of caffeine would decrease.

The retention factor of caffeine would increase.

The retention time and retention factor of caffeine would not change.

if 17.058g of sodium chloride can be formed from 25 g NaNO3, is the limiting reagent CuCI2 or NaNO3?

Graphene has a C-C bond length of 1.42 Å.

(a) Suppose you deposit a single layer of graphene around the entire earth, which has a diameter of 1.27 × 10^7 m. What would be the mass of this graphene layer?

(b) If the graphite in a wooden pencil has a mass of 60 g, what surface area could it cover, if it would be exfoliated as a single layer of graphene?

97.8 grams of sodium fluoride is put into 350. ml of water.

Calculate the

1. Molarity

2. Molality

3. Mass Percent

4. Mole Fraction

What is the appropriate equation for determining the standard deviation of an analytical result from a calibration curve? Define all symbols used.

1) Suppose 500 mL of an 0.200 molar HCl acid is titrated with 70.0 mL of a 1.00 M NaOH solution. What is the final pH of the solution? The error interval is 0.1 pH units.

2) Suppose 500 mL of 0.100 M benzoic acid, which has a pK_a of 4.201, solution is titrated with 75.0 mL of a 1.00 M NaOH. What is the final pH? The error interval is +/- 0.2 pH units.

So i have my chemistry exam next week and this is a question from the practice test. I am wondering more of the how/why for this question than just the answer? How do you tell what is soluable and what isn't how to know what the reaction is gonna be? Is there any easier way to think about this than memorizing the solubility chart. And even with he chart memorized... how do i answer a question like this, am i looking for slightly soluble?

When aqueous solutions of ________ are mixed, a precipitate forms.

A) NiCl2 and AgNO3

B) NaCl and KBr

C) K2SO4 and CrCl3

D) KOH and AgNO3

E) Li2CO3 and KCl

more questions I'm concerned about... again not looking for the answers just like how to go about understanding the solubility and reactions between substances?

Which of the following is an oxidation-reduction reaction? A) HCl (aq) + NaOH (aq) → H2O (l) + NaCl (aq) B) AgNO3 (aq) + HCl (aq) → AgCl (s) + HNO3 (aq) C) BaCl2 (aq) + Na2SO4 (aq) → BaSO4 (s) + 2NaCl2(aq) D) Mg (s) + 2AgNO3 (aq) → 2Ag (s) + Mg(NO3)2 (aq) E) H2CO3 (aq) + Ca(NO3)2 (aq) → 2HNO3 (aq) + CaCO3 (s)

4) The balanced reaction between aqueous nitric acid and aqueous strontium hydroxide is ________. A) 2HNO3 (aq) + Sr(OH)2 (aq) → 2H2O (l) + Sr(NO3)2 (aq) B) HNO3 (aq) + Sr(OH)2 (aq) → Sr(NO3)2 (aq) + H2 (g) C) HNO3 (aq) + Sr(OH)2 (aq) → H2O (l) + Sr(NO3)2 (aq) D) HNO3 (aq) + SrOH (aq) → H2O (l) + SrNO3 (aq) E) 2HNO3 (aq) + Sr(OH)2 (aq) → Sr(NO3)2(aq) + 2H2 (g)
5) In which reaction does the oxidation number of hydrogen change? A) HCl (aq) + NaOH (aq) → NaCl (aq) + H2O (l) B) 2Na (s) + 2H2O (l) → 2NaOH (aq) + H2 (g) C) CaO (s) + H2O (l) → Ca(OH)2 (s) D) 2HClO4 (aq) + CaCO3 (s) → Ca(ClO4)2 (aq) + H2O (l) + CO2 (g) E) SO2 (g) + H2O (l) → H2SO3 (aq)

If we mix 40.0 mL of 3.00 M Pb(NO3)2 (aq) with 20.0 mL of 2.00 x 10-3 M NaI (aq), does PbI2 (s) precipitate from solution? I yes, calculate how many moles of PbI2 (s) precipitate and the values of [Pb2+], [I-], [NO3-], and [Na+] at 25 C at equilibrium?

Given that the solubility constants of HgSO4 and PbSO4 are 6.6x10-7 and 1.6x10-8 respectively, determine the cell potential when the electrolyte is saturated with both
salts at 298 K.

1) Calculate the number of mL of water in 1.00 cubic feet of water.

2) The radius of an AI atom is 0.143 nm. How many AI atoms would have to be laid side-by-side to give a row of atoms 1.00 inch long? (Assume atoms are spherical in shape.)

3) A given point on the moon is 240,000 mi from Earth. How long does it take for light from Earth to reach a reflector at that point on the moon and then return to the Earth if the speed of light is 3.00 * 10^8 m/s?

4) A spherical steel ball has a mass of 3.475 g and a diameter of 9.40 mm. What is the density of the steel in g/cm^3? The volume of a sphere = (4/3)pir^3

The reaction 2NO(g) + Cl₂(g) --> 2NOCl(g) obeys the rate law rate = k [NO]² [Cl₂]. The following mechanism is proposed:

NO (g) + Cl₂ (g) --> NOCl₂(g)

NOCl₂(g) + NO (g) -->2NOCl (g)

a) What would the rate law be if the first step was rate determining?

b) Based on the observed rate law, what can be concluded about the relative rates of the 2 reactions?