(b) Calculate the volume of 0.2M UO3- needed to react with 20.00 cm3 of 0.1M Cr2O72-. 3. 24.40 g of hydrated iron(II) sulphate, FeSO4.xH2O was dissolved and made up to 1.0 dm3 of aqueous solution, acidified with sulphuric acid. 25.00 cm3 of the solution was titrated with 20.00 cm3 of 0.022M potassium manganate(VII) solution for complete oxidation. a) Write the equation for the reaction.
Determine the number of moles of argon and the mass in the sample. 9. A 30.6 g sample of gas occupies 22.4 L at STP. What is the molecular weight of this gas? Think about it!!!!!
Name: Anh Lan Do Course: CHE-131-92L Date: Feb 24th, 2010 General Chemistry 1 Experiment 4 Percent Composition of a Compound Professor Robert M. Cady Questions: 1. According to the law of definite composition, elements form compounds in the same ratios by mass each time the compound is produced. Using the theoretical percent by mass of magnesium in MgO, calculate the mass of oxygen that will combine with 12.25g of Mg and the mass of MgO that will be formed. 2. Which compound has the greatest percentage by mass of Magnesium?
The mass of the pendulum was 100 grams and the string measured 300 mm. Height of Drop (degrees) | Trial 1 (seconds) | Trial 2 (seconds) | Trial 3 (seconds) | Average (seconds) | Period (seconds) | 90 degrees | 26.15 seconds | 25.91
The average bond enthalpies for O—O and O==O are 146 and 496 kJ mol−1 respectively. What is the enthalpy change, in kJ, for the reaction below? H—O—O—H(g) ® H—O—H(g) + ½O==O(g) A. – 102 B. + 102 C. + 350 D. + 394 (1) 7.
Week 5 RES/ 341 Chapter Exercises: 7.54 The fracture strength of a certain type of manufactured glass is normally distributed with a mean of 579 MPa with a standard deviation of 14 MPa. (a) What is the probability that a randomly chosen sample of glass will break at less than 579 MPa? (b) More than 590 MPa? (c) Less than 600 MPa? (Data are from Science 283 [February 26, 1999], p.
BMI=xKG/ym*ym the formula. x=body weight in kilograms y= body height in meter. June 2013 Body Mass Index 3 132 Divide your weight and one kilogram equals 2.2lbs. 2.2= 60 kg (60*0.254) (60/1.52) (39.47 *1.52) Multiple 60 Kilograms and 1 inch equals 0.254 meters. BMI=25.96 this is what I came up with as my BMI figure in the Kg/Meters.
Results: a. Data | Sample 1 | Sample 2 | Sample 3 | Mass of iron compound | .94g | .96g | .97g | Initial burette reading | 0 mL | 0 mL | 0 mL | Final burette reading | 17 mL | 15 mL | 14.5 mL | Volume KMnO4 required | 17 mL | 15 mL | 14.5 mL | b. Calculations 1. MnO4- + 5Fe2+ +8H+ ⟶ 4H2O +Mn2+ + 5Fe3 2. | Sample 1 | Sample 2 | Sample 3 | Moles KMnO4 required | 8.5 x 10-4 mol | 7.5 x 10-4 mol | 7.25 x 10-4 mol | Moles of Fe2+ in sample | 4.25 x 10-3 mol | 3.75 x 10-3 mol | 3.63x 10-3 mol | Mass of Fe in sample | .237 g | .209g | .202g | Mass of sample | .94g | .96g | .97g | % of Fe in sample | 25.2% | 21.8% | 20.8% | Sample 1: .017 L x .050 mol KMnO41L = .00085 mol MnO4 .00085 mol MnO4 x 5Fe2+1MnO4 = 4.25 x 10 -3 mol Fe2+ 4.25 x 10 -3 mol Fe2+ x 55.8g1 mol = .237g %= .237g.94 g x100= 25.2% Sample 2: .015 L x .050 mol KMnO41L = .00075 mol MnO4
A divide by 100 B divide by 1000 C multiply by 100 D multiply by 1000 15 Which of the following is the smallest? A 0.07 7 C ----10 1 B -7 D 73% 7 A ----12 7 C ----16 7 B -9 7 D -8 5 Which one of these decimals could be rounded to 34.71? A 34.715 B 34.7 C 34.707 D 34.7039 1 6 What is -- as a percentage? 6 A 16% B 1.6% -C 16 2 % 3 D 60% 7 What is 37.5% of one day? A 10 hours B 8.6 hours C 9.6 hours D 9 hours 8 Increase $38 by 15%.
In each trial, the initial reading, final reading and the volume of HCl used was recorded down as quantitative results. The average volume of hydrochloric acid was found to be 12.03mL. The amount of sodium carbonate in the 10.00ml of solution was found to b 0.05 mol. The amount of hydrogen chloride that was dissolved in the average volume of acid is 0.365g. Through these calculations, the concentration of hydrochloric acid was found to be 8.3 mol•L-1.