Question

For the following reaction (which is exothermic in the forward determine the effect on the equilibrium position for each change below.) add oxygen to the system add heat to the system cool down the system remove sulfur trioxide from the system add hydrogen to the system Determine the molarity of 1250 mL of a solution made by dissolving 36.063 g Nacl. What volume of a0.115 M HCl solution can be made using 0.30 mole solute? 8.50 mL of 12.4 M.HC1 is diluted to 350 mL. What si the new molarity? Complete and balance the following acid-base reaction What is the pH, pOH for the solution described in # 15?

Answer 1

2SO2 + O2 <-------> 2SO3 + heat (exothermic)

a. The equilibrium will shift to the right in order to consume the O2 added

b. You have to use heat as a product or reagent, in these case the reaction is exothermic so it releases heat, it will be a "product". If we add heat the reaction will shift to the left in order to consume the heat.

c. Opposite of b

d. We are taking away a product so the reaction will shift to the left in order to produce the product.

e. I´m not sure about this one. If the H2 doesn´t react with anyone then the equilibrium position won´t change.

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a. yes, the precipitate will be PbI2

b. yes, the precipitate will be AgCl

c. no precipitate

d. yes, the precipitate will be CaSO4

e. no precipitate

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%m/m= mass solute/mass solution x 100

The density of water is 1g/mL so, 325mL are the same as 325g

%m/m= 85.635g/325g+85.635g x100=20.9%

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mol NaCl= 36.063g/58g/mol= 0.622 mol

M= mol/V(L)= 0.622mol/1.25L= 0.497M

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V= mol/M= 0.3mol/0.115M= 2.61 L

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Ci x Vi= Cf x Vf

Cf= 12.4M x 8.5x10^-3L/0.35L = 0.301M

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3H2SO4 + 2Fe(OH)3 -----> Fe2(SO4)3 + 6H2O

[OH-]x[H+]= 1x10^-14M ----> [OH-]= 2.58x10^-12M

pH= -log[H+]= -log 3.88x10^-3M= 2.41

pOH= -log[OH-]= -log 2.58x10^-12M= 11.59