Formation Of A Precipitate Lab Report

As a group, we obtained our salt mixture of calcium chloride and potassium oxalate, and weighed the mixture. We were able to make an aqueous solution from the mixture and distilled water. We boiled and filtered off the solution, leaving the precipitate. Once the precipitate was dried overnight, it was weighed and the mass was measured. Then we calculated the moles of the precipitate.

When two solutions combine and a solid substance is formed, this solid is called a precipitate. In your experiments, if the clear reactant solutions you combined together formed a cloudy product, then a precipitate (solid substance) was formed. Describe the precipitates (according to color and clarity) and the substances that formed them. (18 points) The combinations that formed precipitates in my experiment were MgSO4 and NH3, MgSO4 and Na2CO3, Na2CO3 and CH3COOH.

(Hint the concentration of calcium ions in well 12 is 4.9 x 10-5 M.) Place 5 drops of 0.10 M NaOH in each of the wells 1 through 12. When the NaOH is added to each well, the initial concentrations of the reactants are halved, as each solution dilutes the other. Use an empty pipet to mix each of these combined solutions by drawing each solution up into the pipet and squirting it back into the well. (Hint the concentration of Ca2 ions in well 12 is 2.4 x 10-5 M.) Allow three or four minutes for the precipitates to form, then observe the pattern of precipitation. At one point the concentration of both ions becomes too low to have any precipitate form. We will assume that the first well with no precipitate represents a saturated solution. Part B NaOH varies, Ca(NO3)2 held constant To check your results, repeat the procedure but use a serial dilution of the NaOH. In a different row, put 5 drops of 0.10-M NaOH in well 1. Put 5 drops of distilled water in wells 2 through 12. Add 5 drops of the 0.10-M NaOH solution to well 2. Use an empty pipet to mix the solution by pulling the solution into the pipet and then squirting it back several times. The solution in this well, 2, is now 0.050 M in OH- ion. Continue this serial dilution to well 12, and then remove 5 drops from well 12. Add 5 drops of 0.10 M Ca(NO3)2 to each of the wells, and mix each with an empty pipet or stirrer. Again, determine the well where no more precipitate appears. Cleanup

To start this experiment, set up the gas collecting apparatus. To start Part A, add approximately 15mL of distilled water to the test tube and record the temperature. Use about half of an Alka-Seltzer® tablet and record the mass. Close the test tube with the stopper with the tubing and tilt the test tube so the water and tablet react. When the reaction is finished, record the volume of CO2 recovered by lining the meniscus of the graduated cylinder up with the water level.

Finally ensure that your results are accurate. You should have a light blue precipitate remaining when the sodium carbonate reacts with the copper chloride and when sodium sulphate ionises with copper chloride no precipitate should have formed.

Both experiments were able to determine the yield of hydrogen gas by testing the effect of limiting reactants, balanced equations, stoichiometry, mole ratios and molar masses. Balanced equations are equations that have a balanced number of moles of each element on both sides of the equation. Molar mass is the sum of the atomic masses of all elements combined in a chemical substance. Mole rations can be determined using the coefficients of the reactants and products in the balanced equation. Mole ratios can be used to relate moles of product formed from a certain number of moles of a reactant. Stoichiometry is the method of using the relationship between two or more substances in a chemical reaction. The limiting reactant of a chemical reaction is the reactant that is used up first in the reaction and limits how much of the product can be formed. In experiment 2-1, a company wanted to know if magnesium or aluminum would be practical to use as an alternative to zinc to produce a given volume of hydrogen gas. In experiment 2-2, the company wants to know how to optimize the production of hydrogen gas and whether hydrochloric or sulfuric acids are reasonable alternatives for gas production. The The reactions performed in experiment 2-1

then we know Ca2+ is involved in the solution. Next we add OH into the

An unknown sample is identified using the relationship between the mass of the product and mass of the reactant in a balanced chemical equation using the involved species molar mass.

This lab revolves around precipitate it reactions. The precipitate reactions happen when it had cations (positive atoms) and anions (negative atoms) in aqueous solutions combined to form an insoluble ionic solid, which is called a participate. In order for these reactions to occur they must be Aqueous and this can be determined by using solubility rules. Predicting these reactions a sign test to find out which ions are present in a solution. Double displacement reactions are the kinds used in this lab. This means that the compound will switch partners and form a bond with a different part. The reaction occurs in Aquarious solution and one of the products that is formed is in soluble.

The objectives for the Limiting Reactant Lab was to determine out of the equation Ba〖Cl〗_(2 (aq))+ 〖Na〗_2 〖SO〗_(4 (aq))→ 〖BaSO〗_(4 (s) ) +2 〖NaCl〗_((aq)) which compound is the limiting reactant from choosing either A or B for the experiment. The purpose for part one is about 〖Na〗_2 〖SO〗_(4 (aq)) and Ba〖Cl〗_(2 (aq))*2H_2 O, when adding water and resulting in 〖BaSO〗_(4 (s) ) is allowed to precipitate. From the two values the percent yield can be calculated. The purpose for part two is the formation of barium sulfate.

The organic layer on the top formed, and was also extracted out through vacuum filtration like the step before. The solid that was produced from the reaction was bright yellow in color. It then was set out to dry for a week, and worked on the next experiment time. After setting the solid aside, the original solution that was still in the separatory funnel, 14 mL of 10% NaOH was added. The aqueous layer was then again separated into a separate flask. This same step was repeated twice more. The aqueous solution that formed was then cooled in an ice-bath. Concentrated HCl was then added until a pH reading of 1 was reached making it an acidic solution. This took 13 mL of HCl to reach the adequate pH. Another precipitate formed from this process, and it was extracted through vacuum filtration. The solid precipitate that was formed was a cloudy white color. It also, was set out to dry for a week until the next experiment time.With the remaining solution in the separatory flask, CaCl2 (a drying agent, which helps dry the precipitate that was filtered out so that no extra liquid will be left over 5), was added. This solution was boiled over a steam bath until no bubbles were present, and left to dry

In this lab there was a performance of a single replacement chemical reaction. The reactants of the reaction was solid iron metal, and copper (II) sulfate solution. This was a gravimetric lab and therefore it was crucial to begin by massing the reactants individually. The copper (II) sulfate was initially a solid. A procedure was conducted to dissolve the copper (II) solid by heating it in water to create the necessary solution. Once that was complete the following action was to react the solid iron and the copper (II) sulfate solution. The single replacement chemical reaction took place and there was a replacement of copper with iron. The products of the reaction was solid copper metal and an iron (II) sulfate solution. The solid copper was

Begin by setting up the ring stand with the clay triangle and record the weight of the crucible. Take the weight of the copper chloride hydrate mass and move it to the crucible where the crucible lid is slightly off and tilted away from you. Set the burner up and make sure to not over heat the compound by moving the flame back and forth under the crucible. After heating and it has cooled observe the substance, if there is no more blue/ green color to it weigh the crucible. After weighing, move the substance to the beaker and pour in the distilled water. Stir using the glass-stirring rod to make sure the substance has completely dissolved. Clean the aluminum wire with the sand paper and wrap around your index finger then put the wire in the copper chloride solution in the beaker. Add hydrochloric acid into the mixture turning the solution clear. You can use the glass-stirring rod to remove the copper off of the wire. After rinsing off the wire, gather the copper that was formed from the reaction and transfer it to the filter paper and allow the vacuum to dry the remaining copper. Place the copper on the watch glass in the drying over for 10-15 minutes. Once the copper is dry take the weight of the copper on the watch glass and record the weight of both. Do this until there is about a 0.005 difference between the starting and the last measurement or the copper. Throw away the chemical in the correct waste container and clean the

Stoichiometry is the numerical relationship between products and reactants;from its calculations, one can predict the products when only the reactants are known or vice versa. Most calculations in chemistry use this in some way (Graves, 2013). Along with stoichiometry, dimensional analysis can also be used, and through the use of both one can calculate the moles of a substance, limiting reagents of a reaction- the substances that limit a reaction’s potential yield, substances that are in excess, number of atoms of a substance, analysis of a combustion reaction,and the molarity of a solution (Burdge and Overby, 2012).

In this experiment, a saturated calcium sulfate was already made and ready to use. 25.00 mL of this solution was then mixed with 10 mL of an ammonia buffer and 1 drop of