CHEM 1520
SI
MON, TUES, & WEDNES
1.Calculate [H3O+] in a solution that has [OH-] = 6.7X10^-2M at 25 celsius, is the solution
neutral, acidic or basic?
2. a solution of NaOH has a PH of 9.52, whats its POH, [H3O+] and [OH-] at 25 celsius?
3. identify conjugate acid-base pairs
CH3COOH (aq) + H2O (l) <====> CH3COO- (aq) + H3O+ (aq)
H2O(l) + F- (aq) <====> OH-(aq ) + HF(aq)
4. Start with 2.50mol of HI into a vessel of 10.32L at 25 celsius, what’s [H2] at equilibrium for the
reaction 2HI(g)H2(g) +I2(g), Kc = 1.26x10^-3
5. chemical reaction
CH4 (g) + 2H2S(g) <==> CS2 (g) + 4H2 (g)
1.00 mol of CH4, 1.00 mol of CS2, 2.00mol of H2S and 2.00mol of H2 are mixed in a 0.250 L at
960 celsiu, Kc= 0.036
so if [CH4] = 4.56M at equilibrium, what are the equilibrium concentrations of the other
substances?
5.an inorganic chemist studying the reactions of phosphorous halides mixes 1.125mol of HCl
with 0.1450 mol of Cl2 and 0.1450 mol of H2 in a 0.500 L container at 250 celsius: HCl (g)
<==> Cl2 (g) + H2 (g) Kc= 5.2x10^-2
a. in which direction will the reaction proceed?
b. if [HCl] = 1.205 M at equilibrium, what are the equilibrium concentrations of the other
components?
6. The system described by the reaction:
CO(g) + Cl2(g) <==> COCl2(g)
is at equilibrium at a given temperature with PCO = 0.30 atm, PCl2 = 0.10 atm, and PCOCl2 =
0.60 atm. An additional pressure of Cl2(g) = 0.40 atm is added. Find the total pressure and the
partial pressure of CO when the system returns to equilibrium