When the solution is acidified during diazotization to form nitrous acid, the sulfanilic acid is precipitated out of solution as a finely divided solid, which is immediately diazotized. The finely divided diazonium salt is allowed to react immediately with dimethlaniline in the solution in which it was precipitated. Mechanism Diazotization: [pic] Diazo Coupling: Methyl orange is often used as an acid-base indicator. In solutions that are more basic than pH 4.4, methyl orange exists almost entirely as the yellow negative ion. In solutions that are more acidic than pH 3.2, it is protonated to form a red dipolar ion.
Title : Reaction of Carboxylic Acids Objective : To Determine The Reaction of Carboxylic Acids Procedure : As referred to Lab manual. Results: A. Salt Formation |Compound |Solvent |Solubility | |Benzoic Acid |Cold Water |Partially soluble | |Benzoic Acid |10 % NaOH |Soluble | B. Salt Hydrolysis Sodium acetate solution changed the color of litmus from red to blue. C. Reaction With Sodium Carbonate Observation : A lot of gas bubbles was released.
Chemistry Lab Types of Chemical Reactions OBSERVATION DATA TABLE Step|Name of Reactants|Description of Reactants|Description of reaction taking place (evidence of chemical reaction)|Description of Products| 1|Zn|Solid, small chunky bits, Silvery-grey, dull|As the Zinc and Sulfur heated up it expanded in the test tube and shot out Zinc Sulfide.-light and heat are produced|White powder was created and the leftovers of the reactions was a black powder.| |S|Solid, resembles powder, Off-yellowOpaque||| 2|KI|-dull yellow liquid-transparent|Instantaneously changed colour to a bright yellow.|-Bright yellow liquid-Opaque| |Pb(NO3)2|-liquid, transparent, very clear-bubbly||| 3|H2O2|-liquid-clear-transparent|A dark grey bubbling liquid was created. It got hotter as it reacted.gas test observations:The splint relit. Oxygen was present.|Oxygen gas was created and a dark grey opaque liquid was left behind in the test tube. | |MnO2|-solid-powder-black||| 4|AgNO3|A clear, transparent liquid.|As the copper reacted with the Silver Nitrate, the ball of Copper changed colour to grey and subsequently developed a ‘furry-like’ characteristic on its coating.|-Clear liquid-Copper changes to a grey colour, ‘furry-like’.| |Cu|-brown/red-solid-stringy||| 5|HCl|A clear, transparent liquid.|When the Magnesium was inserted the HCl liquid started to bubble and fizz releasing Hydrogen. The Magnesium strip dissolved in the process and the test tube got hotter.
Name: Amandeep Sandhu |Date: 06/16/2012 | | |Exp 4: Physical & Chemical Properties |Lab Section: | Data Table: Substance |Color |Odor |Effect of Heat |Cold H2O |Hot H2O |Litmus Test |Dilute HCl |Dilute NaOH | |Mg |Silver Or Gray |Odorless |Forms a white powder |MgO+H2 |Mg(OH2)+H2 |Blue |MgCL2+H2 |MgOH+Na | |Cu | Orange |Odorless |Glows dull red |NO REACTION |Mg(OH2)+H2 |Blue |No Reaction |Cu(OH)2+Na | |Zn | Bluish-white |Odorless |Turns yellow |No Reaction |ZnO+H2 |Blue |ZnCL2+H2 |Na+Zn(OH)2 | |MgO | White |Odorless | |Mg(OH)2) |Mg(OH)2) |Blue |MgCL2+H2O |MgOH+NaO | |CuCO3 | Green |Odorless |Forms Copper Oxide & Carbon dioxide gas |CO2+Ca(OH) 2 |CO2+Ca(OH) 2 |Green |CuCl2+H2CO3 |CuOH+NaCO3 | |Cu(NO3)2 | Blue crystals |Slight | | |Cu2+NO3+H2O |Blue |CuCl2+2HNO3 |CuOh2+NaNO3 | |NaCl |White |Odorless |Melts & become clear liquid | |Na+Cl+H2O |No Color |No Reaction |NaCl+NaOH | | Conclusion: The purpose for this experiment was to combine different chemicals to see if a physical or a chemical change occurred. A physical change happens when the substance changes in appearance yet maintains its physical and chemical properties. A chemical change occurs when a different substance forms with newly formed physical and chemical properties. The first substance was magnesium. Before it was heated, it was a shiny silver strip.
When in flame it produces gas rapidly and bubbles. Liquid turns into gas quickly. When liquid disappears solution (now a solid) turns white | 4 | A Initial temperature is 15 degrees Celsius and the final temperature is 17 degrees Celsius. BThe blue hydrated copper sulphate turned white, evidence of condensation of a clear liquid present on the inside of the test tube.C concentrated sulphuric acid turns black on paper towel and is clear on the white cottonD Carbon pillar grows cause of air bubbles, it is brittle, it is both corrosive with a hole and there is evidence of carbon produced | 5 | No temperature change and iodine brown/yellow gas produced | Properties of Sulphuric acid results table Aim: To investigate and observe the properties of sulphuric acid through five different experiments where we will determine its extent of ionisation in aqueous solution, reaction of sulfate ions, action as a strong acid, affinity for water and action as an oxidising agent. Background: Sulfuric acid (H2SO4) is a diprotic acid (can donate 2 protons to a base).
A. barium sulphate B. calcium carbonate C. silver chloride D. sodium nitrate 3. An element X forms a hydroxide, which dissolves, both in acids and in alkalis. What could X be? A. aluminium B. calcium C. copper D. iron 4. In which reaction is dilute sulphuric acid not behaving as an acid?
Experiment 3.1: Reduction of Benzophenone with Sodium Borohydride. Safety precaution: Sodium Borohydride Toxic & Irritant Wash spillages away with water Light Petroleum Highly Flammable Keep away from flames Ethyl Acetate Highly Flammable Keep away from flames. Residue to non-halogenated waste solvent. Ethanol Flammable Keep away from flames Residue to sink with lots of water. Benzophenone Harmful & Irritant Wash spillages away with water Hydrochloric acid Corrosive & Irritant wash spillages away with water.
Then you will fill a BURETTE with sodium hydroxide (a base) that has a known concentration. Because all the reactants and products in this reaction are colourless, an INDICATOR DYE is added to the sulphuric acid to let us know when all the acid present has been EXACTLY NEUTRALIZED by adding base. Finally, the sodium hydroxide in the burette is added to the acid/indicator solution until the indicator changes colour. (An indicator dye is a chemical that has a different colour in an acid and a base.) PROCEDURE 1.
| 3 drops of 1% dimethylglyoxime solution. | [Ni(NH3)6]2+ + 2H2DMG→ Ni(HDMG)2 + 2NH4+ + 4NH3 | 9 Al3+ | By heating the solution in the hot water bath. | A black gelatinous precipitate was changed to colorless. | 6M NH3 | [Al(OH)4]- + 4H+ → Al3+ + 4H2O | 10 | Centrifuge the solution. | Colorless solution.
Na and Mg are electropositive so they lose electrons in reactions and oxygen atoms form oxide ions O2-. Oxide ions are strong bases because they can accept protons from water. So, sodium peroxide and magnesium oxide are basic. Al2O3 is amphoteric as it has reactions as both a base and an acid. Si, P, S and Cl are increasingly electronegative.