Introduction High performance liquid chromatography (HPLC) is used to separate compounds in a sample, identify compounds and can even be used to deduce the relative amounts of different compounds in a mixture. HPLC works under the same principle as thin layer chromatography using both a stationary and mobile phase. The mobile phase carries the mixture across the stationary phase which is used to separate the compounds. Although in HPLC mobile phase is tailor made to suit the polarity of the analytes. The mobile phase used in this particular experiment was Methanol and 0.1M sodium dihydrogen phosphate at a ratio of 30:70 and a pH of 4.5, slightly acidic.
Since we used our chromatography method, we will be able to figure out which metals our substance contains. It is important to know this especially if we are ingesting and coming in contact with them. Chromatography is a separation technique that works based on the compound interactions as those compounds tend to move within a supporting medium. The compounds interact in two phases; mobile and stationary phase. The techniques help analyzing.
Halides Lab: Background information: Halide ions are reactive and useful. Salts are positively charged ions (metals) combined with any negative ions (nonmetal), and when placed in a solution (water) it separates into the cations and anions that made it up. The Purpose of this lab is to find out how the Halides react with the indicators, and to determine the identity of the two unknown solutions (A and B). Color of solutions prior to experiment: NaF | NaCI | KBr | KI | Unknown A | Unknown B | clear | clear | clear | clear | clear | clear | Color of indicator prior to experiment: 5% Bleach (NaOCI) | 0.2 M Na2S2O3 | 0.1 M AgNO3 | 0.5 M Ca(NO3)2 | clear | clear | clear | clear | Halide solutions | NaF | NaCI | KBr | KI | unknown A | unknown B | Test 1: Ca(NO3)2 | Cloudy White (Nothing) | Clear | Nothing | light yellow (Nothing) | Nothing | Nothing | Test 2, Part A: AgNO3 | clear (Nothing) | Milky White | Gold (Cloudy yellow) | milky green (Cloudy yellow) | turned white, film developed on top layer | Milky | Test 2, Part B: add Na2S2O3 to test tube from part A | Dark Orange/brown | Clear | Dark Gold(precipitate yellow then clear) | milky green (no change) | white precipitation, settled on bottom | Milky | Test 3: NaOCI (Bleach) | Clear (Nothing) | Nothing | Nothing | Orange (Clear) | Nothing | Orange | Unknown A is identified as NaCI (Sodium Chloride), because in test#1 the solution turned a cloudy white color when Ca(NO3)2 (Calcium nitrate) was added. In the first part of test#2, when AgNO3 (Silver nitrate) is added, the solution turned white, with a thin layer of film developing on the surface.
How it was expected the pH at equivalence point was 9.17 this is because of the domination of hydroxide ion in solution. The relationship between the pH and the amount of titrant added offered a better understanding of the equilibrium properties of the acid. Introduction Titrations are a convenient and common method of analysis. Generally titration is an experiment where a known property of one solution is used to infer an unknown property of another solution. There are several types of titrations: Acid-base titrations are based on the neutralization reaction between the analyte and an acidic or basic titrant.
Reactivity of Metals Background Information When a metal (such as magnesium, aluminium, zinc and copper) is mixed with hydrochloric acid, a hydrogen gas is produced. If hydrogen gas is produced, a pop sound should be heard when a flame is held over the substance. On the periodic table the most highly reactive elements are in the first group and the least reactive are in the last group. All metals have the same properties, they are shiny, they conduct heat and electricity, they are malleable which means able to change shape permanently without breaking or cracking, and they are also ductile which means they are able to be deformed without losing their strength. Aim To compare the reactivity of various metals by observing their reaction with hydrochloric acid Hypothesis That the all the metals will produce foam and a pop.
Which one of the following molecules has tetrahedral geometry? A. CF4 B. XeF4 C. BF3 D. NH3 E. AsF5 63. A molecule with 3 single bonds and 0 lone pairs of electrons is predicted to have which type of molecular geometry? A. Trigonal planar B. Trigonal pyramidal C. Bent D. Trigonal bipyramidal E. Linear 64. A central atom with 4 electron pairs (single bonds and/or lone pairs of electrons) could have which of the following molecular geometries?
The separation of cyclohexene could not depend on distillation alone. The method used in our experiment is one way that we could employ to separate azeotropes into its constituents. By adding a chemical that could form complex with one of the component, in our case, CaCl2 forms complex with water,
Explain the difference between polar covalent and nonpolar covalent bonds. ________________________________________________________________________ ________________________________________________________________________ PART 3 1) Explain why beryllium loses electrons when forming ionic bonds, while sulfur gains electrons. ________________________________________________________________
Explain your answer. Useful information to help you complete this worksheet: a) formulas for acids can be found on your reference sheet called "Names of Some Common Ions and Acids". b) Pentane has the formula C5H9O c) Heptane has the formula C7H16O d) Pure sulfurs exists in its natural state as
In an HF molecule the covalent bond is formed by the overlap of the 1s orbital of H and the 2pz orbital of F, each containing an unpaired electron. Mutual sharing of electrons between H and F results in a covalent bond in HF. Molecular Orbital theory: Molecular orbital (MO) theory uses a linear combination of atomic orbitals (LCAO) to represent molecular orbitals involving the whole molecule. These are often divided into bonding orbitals, anti-bonding orbitals, and non-bonding orbitals. A molecular orbital is merely a Schrödinger orbital which includes several, but often only two nuclei.