Given that 11.40 cm3 of K2Cr2O7 was required for complete oxidation, a) Calculate the numbers of moles of Cr2O7- used. b) Calculate the number of moles of Sn2+ that react with Cl2. c) Calculate the concentration of Cl2 in bleach. 5. Pyrolusite is a manganese ore containing mainly manganese (IV) oxide, MnO2.
Main – group metals usually for one cation (positive ion). In a binary ionic compound the metal (cation) is named first. Then the nonmetal (anion) is named, and the suffix -ide is added. To create the formula, you switch the charges, and that tells you how many of each element you will need. For example: Cation Anion Formula Name of Compound Ba2+ I- Ba2+ I- Barium Ion Iodide Ion BaI2 Barium Iodide Type 2: Binary Ionic Type 2 Binary Ionic compounds consist of a metal and a nonmetal.
The pre-1983 penny was made of an alloy of copper and zinc. An alloy is “a substance that has metal characteristics and consists of two or more different elements”. (Coordinated Science, pg.1005) Our objective is to find the metal used inside a post-1983 penny. The accepted value of the density of a post-1983 penny is 7.05g/cm3. “Density is the mass per unit volume of a material”.
The term Cp is the specific heat of the material (at constant atmospheric pressure). Different materials have different specific heat values. The units of specific heat are : Joules/gram deg – C. In this lab we will find the specific heat value of Zinc and compare it to accepted values.This will do by heating a mass of Zinc up to the temperature of boiling water and placing the hot metal into a cup of cold water. The thermal energy that the zinc loses goes into heating up the water in the cup. By knowing the starting temperatures and the final temperature of the water and the zinc, the specific heat of Zinc may be easily obtained.
The only ore that contains chromium is the mineral chromite, which is iron magnesium chromium oxide. Chromite has a high melting point and a stable crystalline structure. The purpose of this experiment is to determine the chemical content of an unknown metal ore sample to confirm that the unknown sample is mineral chromite. The content of the unknown sample will be determined by the use of a type of extractive metallurgy that uses the chemistry of an aqueous solution to remove metals from salts, minerals, and ores. This type of extractive metallurgy is called hydrometallurgy.
During the combustion reaction the ribbon of magnesium metal is heated, it reacts with oxygen from the air in a crucible, producing magnesium oxide: magnesium + oxygen → magnesium oxide We measure the mass of magnesium we use for the reaction, and the mass of magnesium oxide produced at the end of it, then we can work out the mass of oxygen that has been combined with the magnesium. Hypothesis: As we know, the empirical formula of a compound indicates the simplest whole number ratio of atoms of each element present in it. According to Lewis formula of ionic bonding: ionic bonding and the formula of oxidation reaction of Mg: 2Mg + O2 => 2MgO indicates that in one molecule of a magnesium oxide chemical compound there is only one atom of magnesium and one atom of oxygen, therefore by carrying out the experiment the molar ratio of Mg and O is predicted to be 1:1. Method: The materials used in conducting this experiment are as follows: safety goggles, a porcelain crucible with a lid, a length of magnesium ribbon (about 25 cm in length), emery paper, a laboratory balance, a pipeclay triangle, a tripod, a Bunsen burner, and crucible tongs. 1.
When aqueous zinc nitrate is reacted with a limited amount of potassium hydroxide, insoluble zinc hydroxide forms. 2 [pic] + [pic] [pic] Zn[pic] [Eq. 1] Zinc hydroxide behaves as a base when it reacts with acids to form salts and water. In a solution containing excess [pic] ions, Zn[pic] acts like an acid and dissolves forming the complex ion[pic]. 2 [pic] + Zn[pic] [Zn[pic]][pic] [Eq.
The copper is then fed to electrolysis for refining. In an aqueous solution copper is dissolved at the anode, the ion moves across the electrolyte to the cathode and plates out. Cu → Cu2+ + 2 e- (anode) Cu2+ + 2 e → Cu (cathode) Aluminum are commercially extracted mainly from bauxite, which is mostly gibbsite (Al(OH)3). The Bayer process is used to refine the bauxite into alumina or aluminum oxide, which
Synthesis of Colloidal Ag Colloidal silver is made by adding an excess of the reducing agent sodium borohydride, NaBH4 to silver nitrate, AgNO3 . AgNO3 + NaBH4 → Ag + 1/2H2 + 1/2B2H6 + NaNO3 The method used in the procedure for this experiment produces nanoparticles that are about 10-14 nm in diameter. The transmission electron microscope (TEM) image shown corresponds to a sample of silver nanoparticles with diameters that are 12± 2 nm. (The length bar is 20 nm.) Particle size can also be determined using visible spectroscopy.