11) Calculate the osmotic pressure associated with 90.0 g of an enzyme of molecular weight 98,000 g/mol dissolved in 2700 mL of benzene at 30.0 °C. A) 5.99 torr B) 1.96 torr C) 6.43 torr D) 2.48 torr 12) The rate constant for the first order reaction AB+C is k-44 x 10 min-¹ at 57 K. What is the half-life for this reaction at 57 K? A) 32 min D) 1200 min B) 16 min 13) Consider the following reaction: 2 N₂O(g) If the half-life for the reaction is 0.610 s, the rate constant is: A) 1.14 s¹ B) 0,69 sl 14) The decomposition of N:Os(g)-> NO2(g) + NO(g) proceeds as a first order reaction with a half-life of D) 0.32 s¹¹ 30.0 seconds at a certain temperature. If the initial concentration [N2Oslo -0.600 M, what is the concentration after 120 seconds? 4 A) 0.038 M a C) 9.1 min 2 NO(g) + O2(g); rate-k[N₂0] B) 0.100 M C) 0.400 M D) 0.013 M 15) Which equation below best gives the concentration of N₂Os versus time in the previous question Q14? A) [N₂0s] ([N₂Os])/t12 B) [N₂Os] = [N₂O₁Joe C) [N₂0₂]=kt D) 1/[N₂Os] - 1/[N2Oslo + kt C) 0.86 s 16) Given: N2(g) + 3 H₂(g) <-> 2NH₂(g) At equilibrium at a certain temperature, the concentration of NH3(g), H₂(g) and N₂(g) are 0.49 M, 1.61 M and 0.14 M, respectively. Calculate the value of Ke for this reaction. A) 1.26 B) 0.612 D) 1.96 C) 0.411 17) Consider the following reaction: 4 PCb(g) Pa(g) + 6 Cl₂(g) If the initial concentration of PCI(g) is 2.0 M, and "x" is the equilibrium concentration of P4(g), what is the correct equilibrium relation? A) Kc=6x7 B) Ke-6x7/(2.0-x)* 18) Consider the reaction represented by the equation: N2(g) + 3H₂(g) <-> 2NH3(g) Calculate the C) Ke=x7/(2.0-x) D) Kc-(x)(6x)/(2.0-4x)* equilibrium pressures at a certain temperature: PNH)-2.9 x 10 atm, PN-9x10 atm, PH₂-2.7x 10 atm A) 4.9 x10* B) 2.9x10 C) 6.3x10 55 D) 7.8x10 20) A particular vinegar solution has a H₂O concentration A) 17.3 B) 12.1 19) Consider the reaction represented by the equation: Fe (aq) + SCN- (aq) → FeSCN²+ (aq) 6.00 M Fe (aq) and 10.0 M SCN (aq) are mixed at a certain temperature and at equilibrium the concentration of FeSCN2(aq) is 3 M. A) 250x10 B) 95 x10-³ C) 143x10³ D) 303 x104 of 0.013 M. What is the pOH of the solution? C) 12.3 D) 15.8 22) The OH- concentration in a 0.089M of Ca(OH)2 solution is A) 0.178 M B) 0.108 M 21) What is the pH of 42.0 M aqueous solution of NH3 (ammonia). It's Ks- 1.8 x 10¹5. A) 12.4 B) 0.0104 C) 0.778 C) 1.3x10-¹² M D) 12.6 D) 1x10-7 M 23) A solution of 9.00 MHCHO₂ is 0.77% ionized in water. Calculate the K. value for the acid (HCHO2). A) 2.3x10* B) 5.4x10* C) 0.2x10³ D) 0.23 24) When a weak acid is titrated with a strong base, the pH at the equivalence point is ALWAYS A) 7 B)<7 C)>7 D) <1 25) Which one of these statements about strong acid is true A) Strong acid produce solutions with a higher pH than weak acids B) All strong acids have H atom bonded to electronegative oxygen atom C) Strong acids are very concentrated acids D) Strong acids are 100% ionized in water