Add a quarter spatula of copper (II) oxide and warm the solution gently to the 4th test tube and record observations. 7. To the 5th test tube, add 3cm3 of ethanol a couple of drops of conc, sulphuric acid and warm gently. Pour the resulting mixture into 30cm3 of sodium carbonate solution to remove excess acid and smell and record observations. Experiment 2 Time | Observations | 5 minutes | Bubbled like sugar | Once salt water was added | Turned soapy white and thick | Equation: METHOD 1) Put 2 cm3 of castor oil into a 250 cm3 beaker and add 10 cm3 of 5mol.dm-3 sodium hydroxide from a measuring cylinder.
(If any unreacted zinc remained, 10 mL of hydrochloric acid would have been added and warmed.) Only the precipitate, now, remained in the beaker. A spatula was used to transfer it into was watch glass. The precipitate was washed with 5 mL of deionized water and decanted. The precipitate was then washed with ethanol and decanted.
White precipitate shows the presence of chloride (Cl-). Chloride anion equation: HCl(aq) + AgNO3 (aq) → HNO3 (aq) + AgCl(s). The nitrate anion test involves cooling a mixture containing 1 mL of test solution and 3mL 18M H2SO4. 2mL is poured down the inner test tube side and the presence of a brown ring shows nitrate (NO3-) to be present. The carbonate anion test mixes 1 mL of test solution and drops of 6M HCl.
Standard Molar Volume The ultimate goal of this lab was to find the standard molar volume of hydrogen gas (H2). An unknown sample of metal to 3M H2SO4 and an eudiometer filled with water. The dense acid sank towards the bottom to react with the metal sample and form Hydrogen gas. The gas raising to the top of the container caused the pressure in the eudiometer to increase, which lead the water to be displaced. | Trail 1 | Trial 2 | Code | Skinny | Skinny | Mass of Metal | .041g | .027g | Temperature of Water | 296k | 296k | Vapor of Water Temperature | 21.1 mmHg | 21.2mmHg | Barometric Pressure | 76.632cm | 76.632cm | Volume of H2 collected | 29.15mL | 29.2mL | Height of Supported H2 column | 23.95cm | 23.15cm | After the O2 gas had fully reacted, measurements of mass, temperature, vapor, and H2 collected (as shown in the table above) .
Lab 4: Determination of Percent by Mass of the Composition in a Mixture by Gravimetric Analysis Introduction Thermal gravimetric analysis is used to determine the percent by mass is used to determine the percent by mass of a component in a mixture. When a mixture is heated to an appropriately high temperature, one component in the mixture decomposes to form a gaseous compound. The mass of this particular component is related to the mass of the gaseous compound. In this experiment, the percent by mass of sodium hydrogen carbonate (NaHCO3) and potassium chloride (KCl) in a mixture will be determined. Experimental First, we weighed 2 samples, each has 1 gram of NaHCO3-KCl mixture Second, we put the samples in 2 crucibles (A and B) and weighed them.
Let’s call this number X. Then the structural formula of BaCl2 hydrate can be written as BaCl2•XH2O. The reaction of dehydration is |BaCl2•XH2O ( BaCl2 + XH2O |(5) | According to the stoichiometry of the reaction (5) |[pic] |(6) | Where N1 is the number of moles of BaCl2 formed in the reaction (5) and N2 is the number of moles of water lost in the reaction (5). To find out N1 you need to divide the mass of BaCl2 after the reaction by its molar mass. To find out N2 you have to determine the mass of water produced in the reaction.
Chem. 317 Title: The Synthesis of Chloropentaamminecobalt(III) chloride and Linkage Isomerization to Further Synthesis Pentamminenitrocobalt(III) chloride Experimental: Ammonium chloride (.0467 mol) was diluted in concentrated aqueous ammonia (15 ml) in a 125ml Erlenmeyer flask. CoCl26H2O (.0210 mol) was then added to the ammonium chloride solution. The ammonium chloride solution was heated and stirred while 30% hydrogen peroxide (4 mL) was added drop wise. The reaction was monitored and removed from the heat once the effervescence ceased, and then was allowed to cool.