The buffer checks out because pH=pKa ± 1.0. Results: Phosphate buffer: The initial pH for the phosphate buffer is 6.83 and it takes 18 drops to equal 1.0 mL of 1.0 M HCl. The volume of HCl required to break the buffer was 1mL, and the known concentration of the HCl 1.0 M The number of moles of HCl consumed by the buffer was 0.02. [pic] Acetate buffer: The target pH of NaCH3CO2 was 5.25 and the actual measured pH for the acetate buffer was 11.21. The number of drops to equal 1Ml of NaOH is 17 drops.
Convert the length and height measurements for the packet that contains the aluminum shot from units of cm to units of mm using the unit-factor method. Length is 4.5cm conversion factor 1cm = 10mm and 1cm/10mm 4.5cm = 45.0 mm Height = 7.5 cm with the above conversion factor 7.5cm = 75.0mm 2. Convert the temperature measurements for the faucet water and the ice water from oC to oF, using the following equation: oF = 1.8(oC) + 32. Faucet H2O is 25 degrees Celsius F=1.8(25.0)+32 45+32 = 77.0 degrees Fahrenheit (2SF) Ice Water is 10 degrees Celsius F=1.8(10.0)+32 18+32=40.0 degrees Celsius 3. Convert the volumes of the water in
Liquid-liquid extraction Informal report By: Afi Ahmed 100959296 Presented to: Devien Durbano CHM2203 May 26th 2014 Results and calculations Table 1: Mass of mixture containing benzoic acid, 2-naphthol, and hydroquinone dimethyl ether and recrystallization. Mass of mixture: 3.03g Compound | Original mass | Recrystallized mass | Benzoic Acid | 1.01 | 0.14 | 2-naphtol | 1.01 | 0.43 | Hydro. Dimethyl ether | 1.01 | 0.16 | With these values we are able to calculate the percent recovery for Benzoic acid, 2-napthol and the hydroquinone dimethyl ether. 1) Percent recovery for isolation of benzoic acid % Recovery = mass of recovered material _________________________________ x100% mass of starting material = (0.14/1.01) x100% = 13.86% That concludes that the percent recovery is 13.86%. 2) Percent recovery for isolation of benzoic acid % Recovery = mass of recovered material _________________________________ x100% mass of starting material = (0.43/1.01) x100% = 42.57% That concludes that the percent recovery is 42,57%.
Zing Substances. For ionizing substances, such as NaCl , 1mosm is 1mmole times the number of ions formed when each molecule dissociates. One mmole of NaCl is 58 mg, but when it dissociates, it yields 1 mmole of Na+ (23mg) and 1mmole of Cl ( 35mg). Therefore , 58 mg of NaCl is 2 mOsm of NaCl is put into a beaker and distilled water added to make 1 liter, the osmolarity is 2mOsm/l. A) How many mosm solute will 1 gram of NaCl yield?
If 0.100 mol of hydrogen iodide is placed in a 1.0 L container and allowed to reach equilibrium, find the concentrations of all reactants and products at equilibrium. 2 HI (g) === H2 (g) + I2 (g) Ke = 1.84(10-2 [H2]=[I2]= 1.07(10-2 mol/L, [HI]=7.86(10-2 mol/L 6. A 1.00 L reaction vessel initially contains 9.28(10-3 moles of H2S. At equilibrium, the concentration of H2S of 7.06(10-3 mol/L. Calculate the value of Ke for this system.
Pollution www.geobytesgcse.wordpress.com 1. Explain the following water supply pro blems: Yr 11 - Watery World www.geobytesgcse.wordpress.com 2. Fold along here 1. Leakage 2. Uneven Rainfall distribution in the UK 1.
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.
59. Fill in the missing particle or element from the periodic table for X. Indicate mass and charge. a) 60Co ( X + 60Ni 27 28 b) 231Th ( X + 0 e 90 -1 c) X ( 20Ne + 0 e 10 -1 60. Phosphorus–32, has a half-life of 14 days.
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
A. 0.420 M B. 0.567 M C. 0.042 M D. 0.325 M _____ 3. What is the freezing point of an aqueous glucose solution that has 25.0 g of glucose, C6H12O6, per 100.0 g of H2O ? (Kf for water = 1.86 °C /m) A.