Consulting Chemists Institute Introduction The Consulting Chemists Institute was contracted by a local food manufacturer to determine if sodium benzoate‚ a common food preservative‚ undergoes significant chemical changes at the pH level encountered in the acidic environment of the stomach. Experimental Method Sodium benzoate was prepared by addition of an equimolar amount of aqueous sodium hydroxide (3 M‚ ~ 20 ml) to a benzoic acid (1.256 g‚ 10.3 mmol) /water mixture (10 ml). Benzoic
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Experiment 6 :Observation | KA2 | KA3 | Weight of test-tube + solid / g | | | Weight of empty test-tube / g | X1 | X2 | Weight of solid / g | | | Initial temperature of acid / °C | | | Final temperature of mixture / °C | θ1 | θ2 | Temperature change / °C | | | Discussion :[In the experiment sheet‚ the is an error where questions in (c)(i) should be "the heat change involved the reactions involving KA2 and KA3] (c). i : q1 = mcθ1 ; q = (30.00)(4.18)( θ1) = q1 q2 =
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Introduction The VSEPR Theory for this experiment stated that electron group repels against each other and they occupy a lot of space. Scientists use VSEPR Theory to determine the molecule’s geometry by counting the number of electron domains that surround the central atom. Electron domain can be described as a lone pair‚ single‚ double and triple bond‚ and also even free radical. Lone pairs tend to occupy a lot of space and lower the angle of a bond‚ which gives molecular geometry. Lewis
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Enhanced spectrofluorimetric determination of Mebendazole‚ a benzimidazole anthelmintic drug‚ through complex formation with Lanthanum (III)‚ in pharmaceutical preparations and spiked human plasma Abstract The article concerned with the development of simple‚ sensitive‚ rapid and specific spectrofluorimetric procedure for determination of mebendazole. The cited drug was reacted with lanthanum (III) ions to produce highly fluorescent stable complex measured at 340 nm after excitation at 295 nm. Different
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NAROK FORM FOUR DISTRICT MOCK – 2007 233/3 CHEMISTRY PAPER 3 MARKING SCHEME. 1. Table I : School value - 1mk 8cm3 – 9cm3 1mk Decimal / Accuracy 0.1 ( 1mk) Max ( 2mks) Penalise for unrealistic values a) Average volume 8.5 + 8.5 + 8.5 ½ = 8.5 cm3 ½ penalise for missing units 3 b) Moles of solution A 8.5 x 0.25 ½ = 0.002125 ½ moles 1000 c)i) Moles of HCl in 25cm3 of solution D: HCl + NaOH NaCl + H2O
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Lab 12: Reduction of an Aldehyde to a Primary Alcohol by Use of NaBH4Purpose(i)To select an appropriate solvent system. (ii)To synthesize alcohol from aldehyde by NaBH4 reduction. (iii)To identify the aldehyde isomer based on the melting point of the alcohol produced. Procedure(Please refer to the detailed instructions on lab 12 handout)Physical Quantity TableType of substanceMolecular FormulaMolecular Weight (g/mol)Density(g/cm3)Melting Point(oC)Boiling Point(oC)HazardO-vanillinC8H8O3152.15-42
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ACTIVITY: THE CAT’S MEOW / MILK CO-MOTION PURPOSE: To observe the interaction of detergent with the fat of the milk and food color 1. Provide a possible explanation of phenomenon you observed based on the result of your experiment. When food color is added to milk‚ it floats because it is less dense than milk. The non-polar fat in the milk prevents the food color from spreading‚ as it cannot participate in hydrogen bonding with water. When detergent is added to milk and the food color‚ the
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An Introduction to Qualitative Analysis Purpose: Tests the ions of Mg2+‚ Ca2+‚ Sr2+‚ and Ba2+‚ and identify them separately. By using these observations‚ identify the unknown ion. Then tests the ions of SO42-‚ CO32-‚ Cl-‚ and I-‚identify them separately‚ and use the observation to identify the unknown. Procedure Part I - Qualitative Analysis of Group 2 Elements Mix 0.02M K2CrO4 with each Mg(NO3)2‚ Ca(NO3)2‚ Sr(NO3)2 and Ba(NO3)2 together. Secondly‚ mix 0.1M (NH4)2C2O4 instead
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Objective: To successfully separate and identify all three unknown cations‚ found in a mixture and belonging to one of two specific groups (2 from one and 1 from the other). In order to do this we will be using various tests and reactions and observing the effect they had on our solution. Materials: Pasteur pipets Bunsen Burners Stirring rods Excess reagents Hot plates Sample QA unknown 101-5.7 Table of steps and observations: Step/Test |Observation |Inference | |2-1
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The experiment’s objectives were to synthesize alum‚ test for various ions in alum‚ and form crystals in aqueous alum solution. The alum was synthesized from aluminum foil and run through a filtration system to isolate the alum. 2 Al(s) + 2 KOH + 22 H2O + 4 H2SO4 → 2 KAl(SO4)2●12H2O(s) + 3 H2(g) Its composition was analyzed using two precipitation tests and two flame tests. Three methods for growing crystals were then set up for observation next lab. Theoretical yield and percent yield: The theoretical
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