Purpose In this experiment, the limiting reactant of a chemical reaction and the percent by mass composition of a mixture were determined. An unknown salt mixture containing sodium phosphate and barium chloride dihydrate was added to water producing a mixture containing a solid precipitate of barium phosphate. Through the use of filtration, the precipitate was removed from the mixture completely. The filtered liquid was transferred into multiple test tubes, each test tube had either barium chloride or sodium phosphate added into the liquid. The chemical that caused a precipitant to form was determined to be the limiting reactant. The filter containing the barium phosphate that was filtered from the liquid was then dried and later massed. Using …show more content…
Mass of BaCl₂∙2H₂O for trial 1 (m_(BaCl^2∙2H^2 O))=( mol BaCl_2∙2H_2 O)|(244.3 g BaCl_2∙2H_2 O )/(1 mol BaCl_2∙2H_2 O) (m_(BaCl₂∙2H₂O))= 5.187×〖10〗^(-4) mol BaCl_2∙2H_2 O|(244.3 g BaCl_2∙2H_2 O )/(1 mol BaCl_2∙2H_2 O) (m_(BaCl₂∙2H₂O))=0.1267g BaCl₂∙2H₂O The percent composition of the limiting reactant (% comp) was calculated by dividing the mass of the limiting reactant (m_(BaCl₂∙2H₂O)) by the mass of the original sample (m_s) and multiplying the product by 100 Percent composition of BaCl₂∙2H₂O for trial 1 (% comp)= ((m_(BaCl₂∙2H₂O)) )/((m_s) )×100 (% comp)= ((0.1267g BaCl₂∙2H₂O ) )/((1.0490g) )×100 (% comp)=12.08 % BaCl₂∙2H₂O Identification of Limiting Reactant and Percent Composition The unknown sample used in this experiment was # 123. The limiting reactant was determined to be barium chloride dihydrate making sodium phosphate the excess reactant. The average percent composition from trial 1 and trial 2 was found to be 12.68 % BaCl_2∙2H_2 O and 87.32 %
Question3: Experiment 3 The unknown acid sample was 1 • Monoprotic Acid Trails Initial NaOH solution (mL) final NaOH solution (mL) The volume of NaOH to titrate the acid (mL) Amount of Unknown Acid sample 1 (g) The moles of the Unknown Acid (mol) Molar mass of the Unknown Acid (g/mol) A 3.38 28.31 24.93 0.150 0.0026 57.69 B 0.18 29.32 29.14 0.175 0.0029
Next, about 10 mL of both solutions, Red 40 and Blue 1, were added to a small beaker. The concentration of the stock solution were recorded, 52.1 ppm for Red 40 and 16.6 ppm for Blue 1. Then, using the volumetric pipette, 5 mL of each solution was transferred into a 10 mL volumetric flask, labelled either R1 or B1. Deionized water was added into the flask using a pipette until the solution level reached a line which indicated 10 mL. A cap for the flask was inserted and the flask was invented a few times to completely mix the solution. Then, the volumetric pipette was rinsed with fresh deionized water and
In order to begin this experiment, first one must find the balanced chemical equation for the reaction which occurs between the aluminum and copper (II) chloride. This balanced equation being 2Al(s)+3CuCl2 (aq)3Cu(s)+2AlCl3 (aq). After finding this equation, one must use the process of stoichiometry in order to find how many grams of aluminum are needed in order to produce 0.15 grams of copper. In this experiment, the purpose was to produce between 0.1 and 0.2 grams of copper, so one should attempt to produce 0.15 grams of copper seeing as it is the average of those two numbers. The first step in the stoichiometric process which one has to complete is finding how many grams of copper are in one mole of copper.
3mL of the liquid in each of the vials were added into cuvettes and measured in the spectrophotometer. Before each time point the photo spectrometer was zeroed using a cuvette with 3mL of distilled water. If any of the results were considered unusual the machine was zeroed again and the sample was retested. The results from the spectrophotometer test were recorded in a table. The experiment was repeated six times to gain a sample size of six.
In the round-bottom flask (100 mL), we placed p-aminobenzoic acid (1.2 g) and ethanol (12 mL). We swirled the mixture until the solid dissolved completely. We used Pasteur pipet to add concentrated sulfuric acid (1.0 mL) to the flask. We added boiling stone and assembled the reflux. Then, we did reflux for 75 minutes.
I. Title: Mass and Mole Relationships in a Chemical Reaction II. Background: Percent yield is the ratio of actual yield to theoretical yield. Amount in percent of one product formed in chemical reaction. Actual yield is the information found is experiments or is given.
3. Upon adding 20 drops of NaOH, a white precipitate was formed signifying acidic impurity. In the second NaOH mixture, about 20 drops were administered and no precipitate formed indicating that the ample is more pure than before. Data: Weight of flask = 75.10 grams Weight of the flask with solids =
The percent recovery of the copper was calculated using the equation, percent recovery = (the mass of the copper recovered after all the chemical reactions/the initial mass of the copper) x 100. The amount of copper that was recovered was 0.32 grams and the initial mass of the copper was 0.46 grams. Using the equation, (0.32 grams/0.46 grams) x 100 equaled 69.56%. The amount of copper recovered was slightly over two-thirds of the initial amount.
Using the Law of Definite Proportions, the mass of this product was used to determine the number of moles of copper and chlorine in the sample, which led to being able to determine the
Verna Wang Hannah Palmer CHEM 101-069 Lab 11-19-16 Stoichiometry and Limiting Reagents Lab Report Purpose: We are using the reaction of sodium hydroxide and calcium chloride to illustrate stoichiometry by demonstrating proportions needed to cause a reaction to take place. Background: Just like a recipe would call for a specific amount of one ingredient to a specific amount of another, stoichiometry is the same exact method for calculating moles in a chemical reaction. Sometimes, we may not have enough of or too much of one ingredient , which would be defined as limiting and excess reagent, respectively.
After the reaction is finished, the percentage composition of each element in the product can be found and used to calculate the empirical formula, which is the lowest whole number ratio
Abstract In this experiment, the isolation, characterization, and determination of concentration and purity of deoxyribonucleic acid or DNA from Allium Cepa or onion was performed. DNA was isolated through the use of a homogenizing solution. The absorbance ratio was 1.5, which indicates protein contamination. Moreover, the characterization of its components was conducted through the use of different chemical tests.
IV. Data and observations Mass of beaker (g) 174.01 Mass of beaker + NaOH pellets (g) 174.54 Mass of NaOH pellets 0.53 TRIAL 1 TRIAL 2 Mass of potassium acid phtalate (KHP) (g) 0.15 0.15 final buret reading (ml) 30.75
Then, it was heated continuously at least 2 hours till a clear colorless solution was obtained. After finishing the heating process, the tubes which contained the mixture were left to cool and removed from the digestion unit. 50ml of distilled water was added to the digestion tube and 70ml of NaOH was added by the NAOH pump of the system. When the distillation was done, 50ml boric acid (4%) was added into the 250 ml flask. Steam distillation was applied and boric acid & ammonia were obtained.
The chemical equation for this experiment is hydrochloric acid + sodium thiosulphate + deionised water (ranging from 25ml to 0ml in 5ml intervals) sodium chloride + deionised water (ranging from 25ml to 0ml in 5ml intervals) + sulphur dioxide + sulphur. As a scientific equation, this would be written out as, NA2S2O3 + 2HCL + H2O (ranging from 25ml to 0ml in