To do this, first take the number of drops used to achieve the monolayer (1 drop) and convert it to mL using the calibrated number of drops per mL. Then multiply the number of grams of sodium stearate per milliliter of solution. Finally, convert to moles through the molar mass of sodium stearate. HINT: The molar mass of sodium stearate is 296.5 g/mole. Answer = 1.06*10^7 moles/top layer 5.
Using a measuring cylinder, add 50cm3 of 1.0mol dm-3 sulphuric(VI) acid to the thyme extract in the conical flask. 8. Titrate the solution in the conical flask with the potassium manganate(VII) solution until a pale pink colour persists for 10 seconds. 9. Repeat the titration until there are two titres within 0.1cm3 of each other.
Calculate the percent error in the molar mass value. Enter both values in the Data Table. Molar Mass Na2CO3 = 105.99 g/mol – this is the closest molar mass to what I calculated, so the unknown M2CO3 must be sodium carbonate. Percent Error: 93.08g/mol – 105.99 g/mol (100) = 12.18% error 105.99 g/mol DISCUSSION Review the procedure and list the possible sources of error that would cause either the molar mass of the unknown to be (a) too high or (b) too low. The goal of this lab was to discover the unknown group 1 metal (M) of the compound M2CO3 by dissolving the compound in water and adding a solution of calcium chloride, CaCl2 to the solution in order to precipitate the carbonate ions to reveal the molar mass of the unknown element, thus determining the identity of the unknown element.
Titration Aim Part A: To prepare a primary standard and use it to determine the concentration of a sodium hydroxide solution. Part B: To monitor the neutralisation of dilute vinegar by a standardised sodium hydroxide solution to determine the concentration of acetic acid in dilute vinegar. Equipment • 250mL volumetric flask • Oxalic acid dehydrate crystals • Beaker (150mL) • Small funnel • Phenolphthalein • Burette • Wash bottle with distilled water • Electronic balance • Pipette (25mL) • 2 x Beaker 50mL • Burette clamp and stand • Pipette filler • Spatula • Glass rod • pH meter and data logger • Standardised NaOH solution • Diluted vinegar (150mL diluted into 1L with distilled water) • Sample of 0.1mol/L sodium hydroxide solution • Magnetic stirrer with stirrer • 100mL measuring cylinder Method Part A: Preparation of Standard Solution 1. The molar weight (M) of oxalic acid dehydrate was calculated. 2.
The carbonate anion test mixes 1 mL of test solution and drops of 6M HCl. The formation of bubbles shows the presence of carbonate (CO32-). The acetate anion test heats 2 mL of the test solution, 1 drop of 18M H2SO4, and 1 mL (100%) ethanol. A fruity smell, using the wafting technique, shows the presence of acetate
The empirical formula would HO, because the ratio is 1:1. To determine the empirical formula of a compound, the mass of each element must be found. The mass is then converted to the amount of moles of the element. Once the mass of each element is converted to mole, the smallest mole is divided by each of the other moles to determine the ratio of each element. This will give the whole number ratio of each element.
The molar mass of a compound or atom is the mass of 1 mole of anything; this is relative to the atomic mass from the periodic table. The percentage yield from an experiment would be the actual yield divided by the theoretical yield multiplied by 100. We need to know how to balance chemical equations due to law of conservation of mass. Being able to turn moles into mass and mass into moles through the equation “m=nM” rearranged to find out other components. We need to be able to find the limiting reagent and be able to go through the process of gravimetric stoichiometry.
Questions: How would you prepare 10 mL of a 0.25M HCl solution if 1M HCl was available? How much 1M HCl is needed? How much distilled water is used? Dilute 2.5ml of 1M solution with 7.5ml of dihydrogen monoxide. From the graph of Molarity vs. Density, created in Data Table 10, what was the relationship between the molarity of the sugar solution and the density of the sugar solution?
To get accurate result, this titration process are repeated for another two times. The entire procedure by which we obtain the molarity of a solution of one substance (NaOH) from an accurately known amount of another substance (KHP) is called standardization. The average molarity of the sodium hydroxide solution will be used in the next experiment. The second experiment is conducted to determine the molarity of acetic acid and mass percent in vinegar. 100mL of distilled water was added to 10mL of vinegar and followed by 1mL of NaOH was pour into the solution.
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.