The reaction that occurred with this step was displacement and metathesis in the form of gas formation. The balanced equation of this step looks as follows: CuSO4aq+Zns→Cus+ZnSO4(aq) Once this step was finished, the remaining copper was retrieved. First, to recover the copper HCl was added to remove all the zinc. When this happened, a yellow tint was observed in the liquid, as well as bubbling as the zinc was broken down. Once the copper dried out, it was weighed and came to a total of 240 mg.
Results APPEARANCES OF MATERIALS USED Substance Physical Appearance Zinc Carbonate White; powderish Calcium Hydroxide White; powderish; like zinc carbonate 3 M HCL Clear liquid, resembles water 20 mesh granular zinc Grey, metallic, shiny 3% hydrogen peroxide Clear liquid; resembles water Manganese dioxide Very dark grey, black and powdery Copper sulfate Blue, crystalline in structure. Sky blue Zinc iodide Very dark purple, shiny and crystalline in structure 0.1 M acetic acid Clear liquid, resembles water Zinc oxide Very white powdery substance RAW RESULTS Data Specifided (Page 112 CRC handbook) Raw data Volume of Gas Collection Bottle (Average of 3 Trials) 14.04mL Mass of boiling tube (empty) 41.57g Mass of boiling tube with zinc carbonate 43.42g Mass of zinc carbonate 1.75g Volume of water in gas collection bottle after reaction 78.5mL Volume of gas product collected 185.2mL Mass of solid product with boiling tube after reaction 1.11g QUALITATIVE TEST RESULTS Group # Test Observation: Standard Positive/Negative Observation: Experimental Positive/Negative 1 H2 HCL + Zinc bubbling + flaming stick POP! + + flaming splint no POP - 2 CO2 Turned cloudy + Negated from experiment Negated from experiment 3 O2 MgO2 + Hydrogen Peroxide bubbling. Glow stick re-ignited + + wooden splint; glowing stick went out - 4 H2) Added 1 pea size CuSulfate + 1 drop of deionized water; blue, positive + Copper sulfate did not change color when put into wet filter paper - 5 Zn (OH)2 Zinc iodide + 3mL H2O Clear suspension + Visual inspection; cloudy. Acid test= solid + 3M Acetic acid cloudy + 6 ZnO ZnO + Heat yellow Zn Cooled White + ZnCO3 + heat yellow solid.
25 cm3 of a solution of sodium hydroxide reacts with 15 cm3 of 0.1 mol/dm3 HCl. What is the molar concentration of the sodium hydroxide solution? 4. Succinic acid has the formula (CH2)n(COOH)2 and reacts with dilute sodium hydroxide as follows: (CH2)n(COOH)2 + 2NaOH → (CH2)n(COONa)2 + 2H2O 2.0 g of succinic acid were dissolved in water and the solution made up to 250 cm3. This solution was placed in a burette and 18.4 cm3 was required to neutralise 25 cm3 of 0.1 moldm-3 NaOH.
Fluorine is a corrosive pale yellow gas. It is highly reactive, participating in reactions with virtually all-organic and inorganic substances. Fluorine is the most electronegative element. Metals, glass, ceramics, carbon, and water will burn with a bright flame in fluorine. It is possible that fluorine can substitute for hydrogen in organic reactions.
There will have some error. 2) A volatile liquid was allowed to evaporate in a 43.298 g flask that has a total volume of 252 ml. the temperature of the water bath was 100˚C at the atmospheric pressure of 776 torr. The mass of the flask and condensed vapor was 44.173 g. calculate the molar mass of the liquid. T = 273 + 100 = 373 V = 252 mL = 1 L / 1000 mL = 0.252 L P = 776 Torr R= 0.0821 mass of 44.173 - 43.298 g = 0.875g moles of gas = PV / RT = 776 x .252 / 62.363 x (273+100) =0.00841 moles molar mass = 0.875g / 0.00841 moles = 104.1 g/
of moles of Cu2O = no. of moles of O = 0.00875 mol (critical step) mass of Cu2O = 0.00875 x (63.5 x 2 + 16.0) = 1.25125 g percentage by mass of Cu2O = (1.25125 )/2.02 x 100 % = 61.9 % Common mistake: no. of moles of (Al2O3 + Cu2O) = Comment: no. of moles = Example 2 0.144 g of a binary compound of aluminium and carbon reacts with an excess of water to produce a gas. This gas burns completely in oxygen to form water and 72 cm3 of carbon dioxide only.
The half reactions for this system are: Oxidation of 〖Fe〗^(2+): 〖Fe〗^(2+)→ 〖Fe〗^(3+)+1e^- Reduction of 〖MnO〗_4^-: 〖MnO〗_4^-+8H_3 O^++5e^-→ 〖Mn〗^(2+)+12H_2 O Which produces the following overall equation: 〖MnO〗_4^-+8H_3 O^++5〖Fe〗^(2+)→5〖Fe〗^(3+)+〖Mn〗^(2+)+12H_2 O Equilibrium is initially obtained at a very slow rate, therefore the titration is carried out in the presence of excess sulphuric acid (H_2 〖SO〗_4) at a high temperature; in order to drastically increase the rate at which equilibrium is attained. Potassium permanganate acts as its own satisfactory indicator since the reagent 〖MnO〗_4^- anion appears to be an intense purple colour while the product 〖Mn〗^(2+) cation has a colourless appearance. However, the end point must be read quickly as the permanganate end point gradually fades due to the 〖MnO〗_4^- reacting with the 〖Mn〗^(2+) that was formed during the titration. When performing the titration, one must be cautious as side reactions can occur and these side reactions must be prevented using appropriate chemical measures. If an insufficient amount of acid was
The ULTIMATE Chemistry Semester 2 Study Guide! Iron: Fe+2 is ferrous Fe+3 is ferric Copper: Cu+1 is cuprous Cu+2 is cupric Lead: Pb+2is plumbous Pb+4 is plumbic Tin: Sn+2 is stannous Sn+4 is stannic Periodic Table TRENDS * As you move right along the periodic table… decreasing atomic radius, increasing ionization energy, increasing electronegativity, increasing electron affinity, constant shielding * As you move down the periodic table… increasing atomic radius, decreasing ionization energy, decreasing electronegativity, increasing shielding WTF is that stuff? * Atomic radius is the distance between the nuclei of atoms when they are involved in a chemical bond. As you increase the number of protons in the nucleus
c. It burns in an atmosphere of chlorine. d. It is one of the few substances that expands upon freezing. e. The gray form melts at 631°C. 2. The following properties describe zinc.
Since this reaction involves a dramatic color change, it can be used in a titration experiment. Here is the net ionic equation: 12 H+ (aq) + 4 MnO4– (aq) + 5 C2H5OH (aq) ⎯→ 5 HC2H3O2 (aq) + 4 Mn2+ (aq) + 11 H2O (l) deep purple almost colorless 1.00 mL of a white wine was added to excess sulfuric acid solution, then titrated with a 0.100 M KMnO4 solution. It took 20.4 mL of the KMnO4 solution to reach the endpoint. a) Which substance is oxidized, and which reduced, in the reaction? b) What is the molar concentration (molarity) of ethanol in the wine?