However, if the sample does not contain all of these, then it cannot be chromite. Experimental: All participants in the experiment must be wearing safety glasses, long pants, closed toe shoes, and a shirt. The sample may be mineral chromite. Tests should be done to determine if the sample contains magnesium, iron, and chromium (chromite’s components). A spectrophotometer may be used to determine if iron and chromium are in the sample, but magnesium neither absorbs nor emits light energy in the 200-900nm region of the spectrum so it can not be determined by a spectrophotometer.
2) Mineral chromite contains magnesium, iron, and chromium. Tests will be done to determine if these are in the sample. 3) Magnesium does not absorb nor emit
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?
Students are merely learning how to collect data and record. Students are also learning inquiry-based techniques. The next three levels are progressively less teacher oriented and more student oriented. During the structured inquiry students are presented with the question and procedure, but students must formulate the results. During guided inquiry students are provided with only the research question.
(2) Although NH3 forms OH- with water, it did not donate any proton to form OH- but only gain. Therefore, it is a Bronsted-Lowry base but not an Arrhenius base 11. Define the following terms: (5) a. strong acid: acid that
DO NOT attempt to grab the hot crucible or crucible lids with your hands! Always use crucible tongs when handling all hot items and DO NOT place hot objects on the lab bench. Apparatus: Retort stand, , ceramic tile hot plate, ring clamp, pipe clay triangle, crucible and lid, crucible tongs, Bunsen burner. Materials: 25cm of Magnesium ribbon Date Table Item | Mass in grams (g) | Magnesium Ribbon | 0.589 | Mass of clean dry crucible and lid | 49.971 | Mass of crucible lid and contents BEFORE reaction | 50.561 | Mass of crucible lid and contents AFTER reaction | 50.943 | Mass of magnesium oxide compound | 0.971 | Calculations 1. Find the mass of the contents of the crucible.
Properties of Compounds Purpose: The purpose of this lab was to determine whether an unknown substance was ionic or covalent compound based on some common characteristic such as melting point, solubility, and conductivity. Data: Table 1: Properties of Compounds Compound Physical appearance Melting point Solubility in water Solubility on cyclohexane Conducts electricity? H2O Clear liquid Nearly none None Cyclohexane Clear liquid None A Small crystals >277 °C Tube1: Partially Tube 2: Nearly none Strongly B White powder >277 °C Tube 3: Nearly none Tube 4: Nearly none Strongly C White crystals 187.06 °C Tube 5: Freely Tube 6: Partially None D Crystals 195.31 °C Tube 7: Nearly none Tube 8: Freely None E Small crystals >277 °C Tube 9: Freely Tube 10: Nearly none Strongly Results: After dipping the conductivity apparatus into each of the tubes that contained water, the compounds that conducted electricity were Compounds A, B and E. When a compound mixed with water conducts electricity it is considered an ionic compound. If a compound is not ionic when it dissolved in water it will not form ions, but will instead break up into molecules. Therefore compounds H2O, cyclohexane, C, and D are molecular compounds.
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.
Extraction is a process in which metal is removed from an ore by dissolving the metal in a solvent, then recovering the metal from the solution (This is done by dissolving the metal into an acid or water). To isolate certain metals you need to take into account that some are amphoteric. Amphoterism is the reactivity of a substance with both acids and bases, acting as an acid in the presence of a base and as a base in the presence of an acid. A few amphoteric metals are beryllium, tin, lead, aluminum, and zinc. When aqueous zinc nitrate is reacted with a limited amount of potassium hydroxide, insoluble zinc hydroxide forms.
Introduction The major component of eggshells is calcium carbonate (CaCO3). Calcium carbonate cannot be dissolved in water, but can dissolve in an acid using the reaction: 2HCl(aq)+CaCO3(s) Ca2+(aq)+CO2(g)+H2O+2HCl-(aq) This reaction is not used to titrate the CaCO3 because it is very slow when the reaction is close to the endpoint. Instead adding an excess of acid to dissolve all of the CaCO3 and then titrating the remaining H3O+ with NaOH solution can achieve the determination of the amount of acid, which has not reacted with the calcium carbonate. There are differences between amount of the acid (HCl) added and the amount left over after the reaction is equal to the amount used by the CaCO3. The reaction used to determine the leftover acid is: HCl (aq) + NaOH (aq) H2O + Na+ (aq) + Cl- (aq) Aim To measure the percent by mass of CaCO3 in an eggshell.