Wait a second!
More handpicked essays just for you.
More handpicked essays just for you.
Chemistry reactions and observations lab
Chemistry reactions and observations lab
Chemistry reactions and observations lab
Don’t take our word for it - see why 10 million students trust us with their essay needs.
Recommended: Chemistry reactions and observations lab
Introduction For this lab, a number of reactions were performed to aid in the identification of a set of cations. This process was performed to show the effects various chemicals have on the given set of cations. The method through which this experiment was performed included mixing two reactants, a cation and a chemical compound, then examining whether or not a precipitate was created by the mixture. If a precipitate did form, the mixture was then centrifuged to solidify whatever insoluble material was created. After decanting, washing and re-centrifuging the solution, the now semi-pure solid was then submerged in Sodium Hydroxide, while once again recording the appearance of the solution. Many of the methods used in this lab would be most …show more content…
Yellow hue, but no actual reaction between the Aluminum and Ferricyanide Slight yellow hue from the Ferricyanide but once again no actual reaction Blood Red precipitate was formed by combining Cobalt and Ferricyanide Yellow sludgy precipitate was formed Mustard-colored cloud of precipitate material PO43- White cloudy precipitate was formed in solution White precipitate that was dissolved from the addition of Water Dark Purple precipitate was formed by combing Phosphate and Cobalt Thin blue cloud of mineral like material White precipitate OH- White precipitate was dissolved by the Hydroxide N/A Dark Blue precipitate that faded back to the original Pink the Cobalt solution had prior to mixing Cloudy blue precipitate Zinc-Hydron precipitate was dissolved by the addition of Sodium Hydroxide NH3 (NH4OH) N/A N/A The precipitate was barely affected by the Ammonia and remained solid Precipitate dissolved, leaving a blue solution N/A H+ N/A N/A The solid was dissolved and the mixture reverted back to the Cobalt’s original Pink hue The precipitate once again dissolved, leaving a green solution N/A The table above shows the numerous cations and chemicals experimented upon and the visual observations each reaction yielded Data Analysis & …show more content…
I would then add a fair amount of Sodium Triphosphate. If the white precipitate and only the white precipitate remains, I could be sure the solution did in fact only contain Ca2+ Ions. Scenario 2: For scenario two, I would add some Potassium Ferrocyanide to the solution supposedly containing Zn2+ and Ca2+ ions. If the solution yielded a yellow precipitate, Zinc is present. If only a white precipitate remained, Ca2+ is present. If there’s combination of yellow and white precipitate material, then both are present. Scenario 3: For this scenario involving a solution supposedly containing Al3 and Co2+, I would add several drops of Ammonia. If the solution produces a dark precipitate, then cobalt is present. No precipitate would mean that Al3+ was present and a lightly colored precipitate means there is a mix of both.
The purpose of the Unknown White Compound Lab was to identify the unknown compound by performing several experiments. Conducting a solubility test, flame test, pH paper test, ion test, pH probe test, conductivity probe test, and synthesizing the compound will accurately identified the unknown compound. In order to narrow down the possible compounds, the solubility test was used to determine that the compound was soluble in water. Next, the flame test was used to compare the unknown compound to other known compounds such as potassium chloride, sodium chloride, and calcium carbonate. The flame test concluded that the cation in the unknown compound was potassium. Following, pH paper was used to determine the compound to be neutral and slightly
The technique used to narrow down the identity of unknown white compound were solubility test, pH test, flame test, and ion test. The first technique used to narrowed the properties of unknown white compound was using solubility test. To conduct solubility test, 0.25 gram of unknown white compound was dissolved in 100 mL of water. After carefully observing the change while string unknown white compound in water, the unknown white compound was soluble because it dissolved in water completely. Using bursen burner, matches and deionized water, flame test was conducted for unknown compound and it burned lilac color. Then compared the color of unknown white compound to other compound that were narrowed. The results of flame test for compounds that were narrowed down is shown in the following table. The pH test was conducted using litmus paper. 0.50 gram of unknown white compound was measured and dissolved in 10 mL of water in beaker. After dissolving, placed the litmus paper in solution and recorded the pH value of unknown compound which was neutral. Then compared the pH value of unknown white compound to compound that were narrow down. The pH result of the KCL, KNO3, NaCl, and K2SO4 is presented in the following table. The ion test was also conducted in order to make sure that the identity of unknown white compound was matched with the compound that were narrow down. After conducting the test, the result of unknown white compound which formed precipitate compared to KCl, KNO3,NaCl, and K2SO4. The results shown in the following
Cations are positively charged ions, which are attracted to their negatively charged counterparts, anions. Precipitates can form when these cations and anions combine in aqueous solutions; however, precipitates only form if one of the products of the chemical reaction is not soluble in that solution. Solubility is instrumental in understanding how precipitation reactions occur. This is because solubility rules, determine whether a precipitate can form. A precipitate can form if the cation in the compound is soluble when combined with an anion. For example when the solutions silver nitrate and sodium chloride (reactants) are mixed, silver chloride and sodium nitrate (products) are formed. Following the solubility laws, silver nitrate is the precipitate, as it isn’t
Fe 3+ (aq) + S︎CN – (aq) ⇌ Fe ( SCN ) 2 + (aq) ( ∆H = - ve ) Pale Yellow Colorless Blood Red This experiment uses Iron (III) ion and thiocyanate ion ; the two chemicals are yellow colored and colorless, respectively. The product of the forward reaction is Iron (III) Thiocyanatoiron, which has a blood red color.
The goal of these experiments within this lab was to determine the formula and composition of the colored cobalt compound. The beginning experiment was a synthesis. The cobalt compound was synthesized, air dried, then put away for future use throughout the lab. Using the synthesized cobalt compound, % halide, % NH3, and % Co was found. % halide was found using a silver nitrate solution combined with the synthesized cobalt compound.
* Pipette 25cm3 * 2 x 500cm3 beaker * Conical flask 250cm3 * Burette * White tile * Burette stand * Stand * Indicator * 300cm3 of Hydrochloric acid- standard solution (concentration of 0.05M) * Distilled water * Filter Paper * Stirring rod * Funnel Method: * Add 1g of Ca(OH)2 to 300cm3 of distilled water in a 500cm3 beaker. Keep stirring the solution till the solid stops dissolving. This leaves a saturated solution. * Filter off the excess solid into another 500cm3 beaker using a damp filter paper (distilled water). * Repeat the filtration of the solution till there is no solid left.
It is an alkaline solution used to test for the presence of aldehyde groups (RCHO). The reducing sugar (Glucose) reduces the copper (II) Sulphate to Copper (I) oxide. The colour of the precipitate varies dependent on the strength of the reducing sugar present. The colour can vary from blue to red-brick: indicating a high concentration of sugar. Glucose contains an aldehyde group, so it is able to reduce the Benedict's solution and form a precipitate.
In parts A and B, the results were the presence of the lead cation and the barium cation. Lead was identified in part a during step six when the solution turned cloudy and very yellow, indicating the presence of a lead precipitate. During part B, step 13, the solution turned foggy and yellow then settled into a white precipitate, indicating the presence of barium. These results were reasonable. The unknown solution was number 4. During part C, the BaCl2 solution emitted a yellow color when it was placed into the bunsen burner flame. KCl was lavender, NaCl was orange, CaCl2 was also orange, LiCl was magenta, and CuCl2 was green. These results were also expected and coincide well with the given cation flame color table.
Hypothesis is always more than one, it required to making testable hypothesis until the confirmation of the experiment. This lab is to test the seven compound with ferric chloride to confirm that which ferric chloride reacts with. The reaction identifies by compare the intense color change with the experiment control which the control only contains water, ferric chloride, and ethanol. The control of this experiment was color yellow, test tube number 8. If color of liquid change to yellow, it means that FeCl3 not react with compound. When the color changed to other color, wasn’t yellow, it means the functional groups react with the ferric
The purpose of this experiment is to become familiar with metal and nonmetal ions and with tests to determine the presence or absence of these important ions as well as to estimate approximate amounts. This experiment is divided into three sections: cations (six tests), anions (four tests), and identification of an unknown salt. For Fe+3 (Iron) test, place about 2 mL of 5% iron(III) chloride (FeCl3) solution in a test tube and add 10% ammonium thiocyanate (NH4SCN) solution until a deep red color appears. Mix the two solutions gently and record the observations on the data sheet. Next is a flame test for Na+1 (Sodium).
Zinc is the more reactive metal here, so the copper is displaced from the copper sulphate solution. Zinc + Copper sulphate à Zinc sulphate + Copper Zn (s) + CuSO4 (aq) à ZnSO4 (aq) + Cu (s) After the reaction it will be observed that the solution will change from blue to clear, colourless. The copper discharged will be observed as a salmon pink deposit in the base of the vessel the reaction occurs in. Reactions like this can be used to purify metals that are low down in the reactivity series. A more reactive metal can simply be added to purify the less reactive metal, leaving it in its pure state.
In the experiment, there was a very obvious pattern and many effects on the metals that did react with the acid.
A white, powdery appearing precipitate of either BaCO3 or CaCO3 formed in the bottom of the test tube, and the precipitate was washed and the liquid was discarded. Acetic acid was added to the precipitate and was mixed until all of the precipitate dissolved, and then DI water was added. After the solution was no longer cloudy, NH4OH and K2CrO4 were added to the clear liquid and mixed thoroughly and centrifuged. Potassium chromate was added in step 12 because barium reacts with the chromate ion to form a yellow barium chromate solid.2 The resulting dark orange liquid was decanted into a test tube labeled “step 14.” The solid precipitate was analyzed for the presence of barium by dissolving it in HCl, decanting the resulting liquid, and adding H2SO4 to that liquid. No precipitate formed, so the solution was then tested for the presence of calcium. A false positive (the finding of a result that is not accurate) may have occurred if the solution was still cloudy when NH4OH and K2CrO4 were added. The cloudiness of the liquid indicated that the precipitate which could have been BaCO3 or CaCO3 did not fully dissolve, so it could have lead to the presence of a white precipitate in step 13 that did not contain barium. (**Unfortunately, while cleaning up from the previous steps, we discarded the “step 14” test tube, so we watched another group that had calcium in
When the reagents (Aniline and Acetic anhydride) were initially added to the flask, the crude product of acetanilide started to form, along will a small number of impurities. As the compounds were mixed the solution turned a pale-yellow color, with white crystals of acetanilide forming in the solution as the reaction proceeded. As the solution began to heat up the crystals dissolved because the energy (as heat) was being added to the molecules of liquid causing separation between the pure Acetanilide and impurities in solution. The charcoal was then added to bond to the impurities in the solution, separating them from the Acetanilide, and ensuring they would not recrystalized as the solution was cooled. The solution was then left to return to room temperature, and the acetanilide became purified pure crystals, while the impurities remained in the solution and were filtered out. The final product was flaky white crystals of
In this experiment the Sodium Hydroxide solution went through three different phases where its quality and quantity changed. The first phase was called I. Preparing Approximately 0.1M NaOH, 1000mL of clear distilled water was boiled and then chilled to room temp.