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.
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.
Stoichiometry of a Precipitation Reaction October 1, 2013 Chem 131A-011 Partner: Purpose: This lab exercise combines the study of a precipitation reaction with stoichiometry. The amount of product produced in the precipitation reaction will be predicted to determine the theoretical yield. The reactants and products will be measured to determine the actual yield and the percent yield. Procedure: * 1.0 g of CaCl2·2H2O was put in a 100-mL beaker. * 25 mL of distilled water was stirred in to form the calcium chloride solution.
This reaction is carried out by adding a solution of reactant hydrochloric acid from a burette to a solution of sodium hydroxide until just sufficient of hydrochloric acid has been added to react with all of the sodium hydroxide. If the concentration and volume of hydrochloric acid is known the number of moles of sodium hydroxide can be calculated, if the equation for the reaction is known. This procedure is known as a titration and the point at which sufficient volume of hydrochloric acid has been added to the sodium hydroxide to complete the reaction is called the end point. An indicator which changes colour at the equivalence point is often used to indicate the titration end point. This standardized solution of sodium hydroxide can then be used to determine the concentration of acid in the sample of gastric juice.
The chemical equation to be used is : 2NaHCO3(s) Na2CO3(s) + CO2(g) + H2O(g) In the second part, 1.0 M HCl will be titrated into a solution with a known amount of sodium carbonate (Na2CO3), the pH will be measured as it becomes more acidic and the equivalence point (the point at which HCL and Na2CO3 reach equilibrium) determined. We will calculate the moles of Na2CO3 by dividing the grams used by the molar mass of sodium carbonate. Then, the moles of HCl required to neutralize Na2CO3 will be determined by using the mole to mole ratio in the chemical equation. Finally, the molarity
Gravimetric Determination of Sulfate Purpose The purpose of this lab is to determine the percentage of sulfate in the hydrate by precipitating the sulfate as barium sulfate. Materials Filler paper Sodium sulfate Graduated cylinder Bunsen burner Watch glass Beakers (250 mL, 400 mL) Rubber bulb Graduated pipette Beaker tongs Funnel Filter Paper Sodium Sulfate Drying oven Wash bottle Stirring rod Silver nitrate Hydrochloric acid Distilled water Small test tube Procedures First, .4861 grams of sodium sulfate was placed into a clean 400mL beaker. Exactly 200mL of water and 1mL of HCl was added to the same beaker. A watch glass was placed on the beaker and the solution was heated using the Bunsen burner to a gentle boil. The watch glass was removed with the beaker tongs.
Pour all the filtrate and washings into a 250cm3 volumetric flask. Make up to 250cm3 with 1.0mol dm-3 sulphuric acid(VI) acid. Stopper the flask and invert several times to thoroughly mix the solution. 5. Fill the burette with 0.005mol dm-3 potassium manganate(VII) solution.
Let’s experiment and observe Whether these ions will have a reaction or indeed soluble in water. Experimental Procedure Let’s begin this experiment by obtaining a 100ml beaker from our equipment tool bar list, then we are going to add 50ml(s) of Potassium Chromate 1M solution to that beaker, The next step we are going to add another ionic compound of 50ml of Lead (11) nitrate 1M into the same beaker as the Potassium Chromate. As we observe the beaker, we notice a reaction has occurred and a precipitate has formed and settled on the bottom of the beaker. The next step is we are going to filter the resulting precipitate into a 250 ml Erlenmeyer Flask with a Buchner funnel. Now that we have filtered the precipitate, we will then place the resulting precipitate into a test tube to measure the weight.
The number of moles of that reacts with the calcium carbonate will vary according to the mass of calcium carbonate that is present in eggshell. Control variable: Concentration of sodium hydroxide. The concentration of NaOH is used for titration is kept constant this will give the accurate measurements of the amount of HCl that did not react with the calcium carbonate. Apparatus * Mortar and Pestle * Standard Lab Balance * Hot Plates * 200ml beaker * Measuring cylinder (10ml, 100ml) * Pipette * Burette * Conical Flask * Bunsen burner Any reagents used in this experiment * Eggshell * NaOH 1moldm3 * HCl 1moldm3 * Phenolphthalein Procedure
Exp 3 The purpose of this experiment is to determine the reaction that happens to the calcium carbonate when it is added to HCl acid. Exp 4 The purpose of this experiment is to test 2-3 different indicators in acidic and alkali solution. Exp 5 The purpose of this experiment is to test the pH value of random substances and determine whether they are acidic or alkali. Materials used: Equipments and materials 1) Universal indicator 2) 2 mole/dm3 of Hydrochloric acid (HCl) 3) 2 mole/dm3 of sodium hydrochloric(NaOH) 4) Test tube 5) Magnesium ribbon (Mg) 6) Calcium Carbonate in the form of limestone or marble (CaCO3) 7) 2-3 indicators (bromothyle, litmus and sulfone phthalein) 8) Test tube rack 9) Glass stirring rod 10) Beaker 11) Pipettes 12) Demineralized water 13) Random substances (baking soda, pineapple, pear, orange, sugar etc ) Theory Acids are chemical substances, which have a sour taste. There are two types of acids, weak acids and strong acids.