20 20 5 10 10 1.00 15.81 0.06 Graph Discussion: From the table and graph above it was observed that decrease in the concentration of hydrogen peroxide increased the time for the blue black colouration to appear, which gave rise to decrease in the rate of the reaction. The volume of distilled water added as shown in the table was to reduce the concentration of the hydrogen peroxide. The same trend was observed in the dilution of potassium Iodide. In the graph the volume of hydrogen peroxide was used as the concentration since concentration is proportional to volume. Conclusion It was clearly observed that the decrease in the concentration of hydrogen peroxide lead to increase in the reaction time and also decrease in the rate of the reaction.
The overall goal of this lab was to produce an unknown oxalate compound, find its percent composition, calculate its molecular formula, and determine the limiting reactant in its formation. A reaction between iron III chloride hexahydrate and potassium oxalate monohydrate produced 3.307g of potassium trioxalatoferrate (III) trihydrate with a 62.0 percent yield. A permanganate titration determined the average percent composition of oxalate was 53.3% with a 2.22% standard deviation. The percent composition revealed the compound’s empirical formula to be FeK3(C2O4)3•3H2O. Potassium oxalate proved to be the limiting reactant.
This helps to indicate whether or not the reaction follows Markovnikov’s Rule, which states that the electrophile (E+) will add to the carbon involved in a double bond that produces the most stable carbocation. If the rule is followed, the reaction will proceed according to the mechanism in Figure 1. In the silver nitrate test, the alkyl bromide is added to AgNO3. The rate of precipitation with 2° should be faster than the solution with the 1° alkyl halide. In the sodium iodide test, the alkyl halide is added to sodium iodide in acetone.
Lab Report Experiment 6 Rates of Chemical Reactions By Nikhola Mirashirova Lab Partner: Dina Abetova Section 3, Saturday October 31, 2015 Introduction Rate reaction is the measure of the change in concentration of the reactants or the change in concentration of the products per unit time.1,2 Rate law for this experiment: Rate = k(I-)m(BrO3-)n(H+)p There are several factors which affect the rate of reaction: catalyst, reactant concentration, and temperature.1,2 A catalyst is a substance that changes, increases or decreases, the rate of a chemical reaction but is not being used up during the reaction.3 It provides an alternative way, so that the rate of reaction changes.4 Catalyst, which is used in this experiment, is (NH4)2MoO (0.5 M). In this experiment rate of reaction with different reactants concentration: KI (0.010 M), KBrO3 (0.040 M), and HCl (0.10 M) will be observed. So, this is reaction between iodide and bromate ion under acidic conditions: 6 I- (aq) +BrO3-(aq)+ H+(aq)→ 3I2(aq) + Br-(aq)+ 3H2O The end of the reaction, will be determined by observing color change of solution. Thus, solution should shange color to blue. Blue color appear because of starch indicator.
They tested how the temperature would affect the rate of reaction. This was observed by the amount of time it took for the solution to change colors. For many chemical reactions there is an optimum temperature at which the chemicals will react with each other. As was found in their experiment, the temperature affected the rate of reaction. (Deoudes, 2010).
In addition, phenolphthalein was added as an indicator. The aliquots were titrated against sodium hydroxide (NaOH) solution until end point was reached, after which volume of NaOH consumed was recorded. The value of the rate constant, k, obtained was 0.0002 s-1. The experiment was then repeated with 40/60 V/V isopropanol/water mixture and a larger value of k = 0.0007 s-1 was obtained. We concluded that the rate of hydrolysis of (CH3)3CCl is directly proportional to water content in the solvent mixture.
Balanced Chemical Equation: Cu(s) + 4HNO3(aq) —> Cu(NO3)2 (aq) + 2NO2 (g) + 2H2O (l) Reaction 2: when sodium hydroxide (NaOH) is added to copper (II) nitrate (Cu(NO3)2), a double displacement reaction will occur. Copper and sodium will displace each other to create copper (II) hydroxide and sodium nitrate. Balanced Chemical Equation: Cu(NO3)2 (aq) + 2NaOH (aq) —> CuOH2 (s) + 2NaNO3 (aq) Reaction 3: When copper (II) hydroxide is heated, a decomposition reaction will occur. The reaction will decompose forming two compounds, Copper (II) oxide, and water. Balanced Chemical Equation: Cu(OH)2 (s) + Heat —> CuO (s) + H2O (g) Reaction 4: when a sulphuric acid is added to the solution that contains copper (II) oxide, a double displacement reaction will occur.
Idoine reduced into idoine ion ， which changre from brown to colourless. In test tube F, the iodine solution change from brown to purple . It is because the salt has a function of cofactor which will shorten the time for amylase to take to break down the
The aim of the experiment is to investigate the catalytic effect at different conditions on the hydrogen peroxide decomposition. Hydrogen peroxide which have a chemical formula of (H2O2) is the product of metabolism that must be decomposed. Varies of enzyme catalyst (catalase) and inorganic catalyst (manganese dioxide) were used to study the effects. The effervescence occurs showed that the presence of oxygen gas. The oxygen gas collected was tested by using glowing wooden splinter test.