As the drops are being added, a distinct yellow color can be observed where the drops were landing in the solution. The solution then turned blue-green and very cloudy when about 50 drops of NH3 were added. A distinct dark blue color was evident where the drops were landing in the solution. Also, there was an emission of gas while the NH3 was being added. Another change of color and clarity is evident when 15.0mL of H2SO4 was added to the
Calculate the molarity of the original vinegar solution and its concentration in gdm-3, given that it reacts with NaOH in a 1:1 ratio. 7. 2.5 g of a sample of ethanedioic acid, H2C2O4.nH2O, was dissolved in water and the solution made up to 250 cm3. This solution was placed in a burette and 15.8 cm3 were required to neutralise 25 cm3 of 0.1 moldm-3 NaOH. Given that ethanedioic acid reacts with NaOH
Ag+ Add drops of HNO3(aq) and test with blue litmus until acidic. The litmus paper turs red. The white precipitate reappears HNO3(aq [Ag(NH3)2]+ (aq) + Cl-(aq) AgCl(s)+2 NH3(aq) 2NH3(aq) +2H3O+(aq) 2NH4+(aq)+2H2O(l) 7. Cu2+ Add NH3 (aq) to the supernatant. Formation of a deep-blue solution NH3(aq) Bi3+(aq)+3NH3(aq)+3H2O(l) Bi(OH)3(s)+3 NH4+(aq) Cu2+(aq)+ 4NH3(aq) [Cu(NH3)4]2+(aq)
The Cover Sheet to the Confidence Report South Street Seaweed Seaport Tabulated test Results Name of Test Requirements Result Test for Iodine If the mineral oil turns a shade of purple (either dark, or light such as pink), then the Tincture is positive for iodine. The solution became light lavender/pink. This shows that the tincture is positive for iodine. Test for Iodide ion A few things can happen: 1) A white precipitate only, indicating chloride ion is present predominantly (Na Cl in salt water). 2) A yellow precipitate only, indicating iodide ion is present predominantly.
Determination of the percentage purity of aspirin Introduction The aim of this experiment is to determine the percentage purity of 2-ethanoyl-hydrobenzoic acid (acetylsalicylic acid) in aspirin tablets. A known amount of standard sodium hydroxide solution is used in excess to hydrolyze a known mass of aspirin tablets: CH3COOC6H4COOH(s) + NaOH(aq) → C9H7O4Na(s) + H2O(l) The unused sodium hydroxide which remains is then titrated with standard nitric acid solution of 1 mol. NaOH(aq) + HCl(aq) → NaNO3(s) + H2O(l) The amount of alkali required for the hydrolysis can now be calculated and from the above equation, the amount of moles of acetylsalicylic acid which has been hydrolyzed can be found. Research question | Independent variablesnumber
In this lab, two different titrations were performed with three different antacids to determine which brand is the most effective at the cheapest price. The antacids were ground up separately and approximately 0.2 grams of it was placed in a flask. Methyl Orange, an indicator, and a stir bar were added into the flask. The flask was then put on a stir plate which was under a buret with 0.1M hydrochloric acid. The acid was poured into the flask until there was a permanent pink colour.
Gradually turning yellow. The substance that was left on the spatula was originally green but turned red after being exposed to the flames. | Strontium Chloride SrC12 | The flames emitted became red then turned into a yellowish orange color and gradually turned green with a little bit of purplish blue.
They are methyl red, Simmons citate and H2S producing positive. Salmonella suspect colonies grow as red colonies with a black center in Xylose Lysine Deoxycholate (XLD) agar. Red slant (alkaline) and yellow butt (acid) with H2S production is another characteristic of Salmonella in Triple Sugar Iron (TSI) agar (Quinn et. al., 1994). On the other hand, serology or serotyping is based on the characterization of the somatic (O), flagellar (H), and envelope (V)
___________ 8. After adding starch to iodine, what was the color? _________________ 9. Which of the tubes on the right was a positive test for starch, the one of the left or the right? ________________ How did you know?
Since vinegar is an acid, you know that vinegar was not in the solution and it must be something else. You decided to investigate if the new wave of Vitamin Water is pH neutral: neither too acidic nor too basic. Using BTB (bromothymol blue), you select five flavors of Vitamin Water to rest. Three of the flavor-samples turn a murky green, indicating the likelihood of acid/base balance. Of the two remaining, one turns slightly yellow, while the other remains blue.