Calculate the volume of 0.250 M H2SO4 that contains 0.250 g H2SO4. 0.250 g H2SO4 x 1 mole x 1 L = 0.0102 L 98.12 g 0.250 mole 5. 1.50 g of NaCl is dissolved in 100.0 mL of water. Calculate the concentration. 6.
Calculate the value of Ke for this system. 2 H2S (g) === 2 H2 (g) + S2 (g) [1.1(10-4] 7. At a given temperature, the following system has an equilibrium constant, Ke, of 0.27. C(g) + B(g) === 2 E(g) The system was established by placing 8.00 moles of C and 5.0 moles of B in a 4.0 L vessel. Calculate the concentration of all substances at equilibrium.
(4.) What is the total pressure(mmHg) of a gas mixture containing argon gas at 0.25 atm, helium gas at 350 mmHg and nitrogen gas at 360 torr. (Hint: use Dalton’s Law of Partial Pressures). *Dalton’s Law: a gas law stating that the total pressure exerted by a mixture of gases in a container is the sum of the partial pressures that each gas would exert alone. *Partial Pressure: the pressure exerted by a single gas in a gas mixture.
As the number of moles decreases, the volume decreases Summary: Combined Gas Law: PV/nT = constant (T in Kelvins) P1V1/n1T1 = P2V2/n2T2 Ideal gas Law: PV = nRT R = .0821L atm/mol K Gay-Lussac’s/Avogadro’s Law of Combining Volumes Equal volumes of any gases at the same temperature and pressure contain the same number of moles of gas. The coefficients of a balanced equation can be used to calculate relative volumes. Standard Molar Volume: At standard temperature and pressure (STP = 1atm and 273.15K) 1 mole of any ideal gas has a volume of 22.4L Variations on the ideal gas law equation: PV = mRT/M (m = sample mass, M = molar mass of the gas) d = MP/RT (d = density of the gas in g/L) Examples: 1. Calculate: a. The new pressure in a closed container if a 5.0L volume of gas at 2.5atm has its volume increased to 7.5L.
1 / [CO2] C. [CaO][CO2] / [CaCO3] D. [CaCO3] / [CaO][CO2] _____ 13. The value of Kp for the reaction 2 NO2 (g) [pic] N2O4 (g) is 1.52 at 319 K. What is the value of Kp at this temperature for the reaction N2O4 (g) [pic] 2 NO2 (g) ? A. -1.52 B. 1.23 C. 5.74 X 10-4 D. 0.658 _____ 14.
How many moles of gas does it take to fill a 1.0 L flask at a pressure of 1.5 atm at 100 celsius? (.049 mol) 2. What is the atmospheric pressure if the partial pressures of nitrogen, oxygen and argon are 604.5 mm Hg, 162.8 mm and .5 mm respectively? (767.8 mm Hg) 3. Describe the
E) Water is a compound. 5. Which of the following are chemical processes? 1. rusting of a nail 2. freezing of water 3. decomposition of water into hydrogen and oxygen gases 4. compression of oxygen gas A) 1, 3, 4 B) 2, 3, 4 C) 1, 4 D) 1, 2 E) 1, 3 6. Which one of the following is the highest temperature?
If 1.40 g of N2 are used in the reaction, how many grams of H2 will be needed? ans. 0.303 g H2 4. What mass of sulfuric acid, H2SO4, is required to react with 1.27 g of potassium hydroxide, KOH? The products of this reaction are
There will have some error. 2) A volatile liquid was allowed to evaporate in a 43.298 g flask that has a total volume of 252 ml. the temperature of the water bath was 100˚C at the atmospheric pressure of 776 torr. The mass of the flask and condensed vapor was 44.173 g. calculate the molar mass of the liquid. T = 273 + 100 = 373 V = 252 mL = 1 L / 1000 mL = 0.252 L P = 776 Torr R= 0.0821 mass of 44.173 - 43.298 g = 0.875g moles of gas = PV / RT = 776 x .252 / 62.363 x (273+100) =0.00841 moles molar mass = 0.875g / 0.00841 moles = 104.1 g/
(2 points) Mg(s) + 2 HCl(aq) → H2(g) + MgCl2(aq) 2. Determine the partial pressure of the hydrogen gas collected in the gas collection tube. (3 points) partial pressure H2 = total pressure - vapor pressure of water = 746mmHg - 19.8mmHg = 726mmHg 3. Calculate the moles of hydrogen gas collected. (4 points) n = 125 4.