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International Baccalaureate: Chemistry
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Calculate the molar volume of H2 gas at room temperature. a) theoretical value from Vm =22.44 l/mol at STP. b) experimental value from your data. Equipment: * 2 flasks (volume at least 600ml) * large container (volume at least 3,5 l) * Magnesium ribbon * 30ml of Hydrochloric acid * thermometer * a hose (to cover the reaction flask) Observations: * Magnesium ribbon was a little oxidized for it had lost some of its shine. * When the collection flask was turned around and placed in the water filled container, there were tiny air bubbles on the inside walls of the flask.
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FACTORS THAT AFFECT THE LIGHT ABSORBED BY A TRANSITION METAL COMPLEX How does the concentration of Nickel Sulphate solution affect its absorbency of light?
(mol dm-3) Volume of 1M Aqueous NiSO4 Solution (cm3) Volume of deionized water(cm3) 1.00 10 0 0.90 9 1 0.80 8 2 0.70 7 3 0.60 6 4 0.50 5 5 0.40 4 6 0.30 3 7 0.20 2 8 0.10 1 9 Making the dilutions: 1. Use two graduated pipettes, one for the deionized water and the other one for the 1M Aqueous Nitrate Sulphate solution to make the dilutions of Nitrate Sulfate from the table above. 2. Pour the water and the solution into a beaker and mix thoroughly. 3. Use a glass dropper to take a sample from the dilution and store in one of the cuvettes, make sure there are no air bubbles.
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EXPERIMENTAL DESIGN Aspect 3 MATERIALS USED > Apparatus * 250 cm3 beaker x 2 * 100 cm3 conical flask x 3 * 100 cm3 measuring flask x 2 * 10 cm3 measuring flask x3 * Electronic weighing machine x 1 * Watch glass x 1 * Thermometer x 1 * Test tube x 1 * Dropper x 1 * Ice box x 1 * Burner x 1 * Glass rod x 3 * Funnel x 2 * Filter paper as required * Safety goggles x 1 pair * Apron x 1 pair > Chemicals required * Acetanilide * Glacial acetic
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An electrochemical cell makes use of a redox reaction and uses the chemical reaction to produce an electric current. The two metals that will be used in this experiment are Copper and Zinc, and their salts are used in an aqueous form in the container, being CuSO4 and ZnSO4. A salt bridge that is dipped in KNO3 will be used. The following reaction takes place in each half cell: Cu (s) -->Cu2+ (aq) + 2e- Zn (s) -->Zn2- (aq) + 2e- Independent Variable: Temperature of the electrolytes (�C)
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- although the amount of hydrochloric acid needed to neutralize the marble powder differs according to the strength of the acid, the volume must be kept the same so as to make it a fair test. In order that the acid should not run out on the weakest concentration of acid, the volume will be 50mL � 2mL for each trial, which is enough to accommodate all of the concentrations. This value hasn't been calculated and is a random value. > The apparatus that is used will be kept constant throughout the experiment so that it is a fair test.
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Aim: To calculate the activation energy (EA) for the reaction between Br- and BrO3- in acid solution
The bromine produced will react with the phenol, until all the phenol has been consumed. At this point the bromine will bleach the indicator - so sudden change in the colour of the indicator is used as a measurable "end point" for this reaction. By carrying out this reaction at different temperatures the time taken to react this end point in each case can be recorded. If we let the concentration of Br2 (from start to end point) = c (and note this is a constant in the reaction at different temperatures) And the time taken for this change = t Then: k ?
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Volume of Hydrogen Produced (cm3) 0.00086 17.7 0.00129 27.4 0.00172 36.3 0.00215 46.3 0.00258 54.9 0.00301 56.4 0.00344 67.8 0.00387 79.1 Qualitative Observations: When attempting to wrap the copper wire around both strips of magnesium the shattered into several pieces which contribute to the uncertainties, the broke into pieces due to the size of the strips of Mg. When the Magnesium(s) was added to the Hydrochloric Acid (3mol) (l) it floated in the acid and slowly dissolve producing gas and lowering the water level of the replacing it with hydrogen gas which was being produced.
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Repeat step 1, this time using 10 ml of water instead of ethanol. 4. Observe what happens, and after the reaction is complete keep the test tubes aside. 5. Now take a clean test tube and add 10 drops of ethanol to it followed by 10 drops of glacial acetic acid followed by 6 drops of concentrated sulphuric acid. 6. Warm the mixture without boiling it for 5 minutes. 7. Pour the contents into 50 ml of water in a beaker and smell cautiously. 8. Repeat the steps 5 - 7 but this time using 2-hydroxybenzoic acid (salicylic acid)
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Aim: To study and investigate the effect of temperature on the rate of the reaction between sodium thiosulphate and hydrochloric acid.
The rate of a chemical reaction depends on a number of factors. 1. Size of particles 2. Concentration 3. Temperature 4. Addition of a catalyst 5. Pressure of a gaseous reactant During the experiment, as we increase the temperature the average kinetic energy of the particles increase, resulting in a larger number of particles having activation energy. This in turn results in more effective collisions, increasing the speed of reaction. The reaction between sodium thiosulphate and hydrochloric acid proceeds to the following chemical equation: Na2S2O3(aq) + 2HCl(aq) ? 2NaCl(aq) + SO2(aq) + H2O(l) + S(s) This equation can also be represented in the ionic-equation form in the following manner: S2O32- + 2H+ ?
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Part 5: Polarity of the liquids: As water conducts electricity, it should have some type of charge that will make it polar. In the case of the two organic compounds I don't think they are polar because they don't conduct electricity Results: Part 1: Solubility in liquids Solutes with Water Substance Observations Calcium Chloride Dissolved instantly, some bubbles appeared, an homogeneous colourless mixture was produced Graphite No dissolution, graphite ended on the bottom of the test tube. Iodine No dissolution, iodine went to the bottom of the beaker, water became pale yellow.
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It varies according to the change for the magnesium used. * The controlled variables are the pressure and temperature in the room. Methods used 50 mm of magnesium ribbon was taken and weighed. Then 10 cm3 of HCl was poured into the eudiometer. Then water was carefully filled above the HCl in the eudiometer. Here water and HCl should not mix with each other. Then the magnesium ribbon was tied around a piece of copper wire on a rubber stopper. This rubber stopper with magnesium tied to it was used to close the eudiometer.
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Roughly 35% is emitted as light leaving 65% as heat energy.1 Therefore, the bulb emits 0.65x720=468 J or 0.468 kJ of heat energy. By filling the container to the brim with water, we used a measuring cylinder to measure the volume of the water which was to be: 992mL The theoretical specific heat capacity2 of methane was found to be 2.226J/g.C The table in the next page shows temperature readings in degrees Celsius of a methane sample collected in the closed container that was heated by this bulb over a period of 32 minutes.
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Investigating the effect of different liquid densities on the time taken to release 25 ml of alcohols
* 125 ml propan-1-ol CH3(CH2)2OH 98%. * 125 ml butan-1-ol CH3(CH2)3OH 99%. * 125 ml octan-1-ol CH3(CH2)7OH 94%. * Thermometer (Uncertainty: � 0.0500 oC). * 5 x funnels. * 50 ml conical flask. * Casio stop watch (Uncertainty: � 0.0100 seconds). * Distilled water. * Risk assessment: * The procedure uses poisonous alcohols. Notably, suggested by Department of Chemistry - Imperial College London (2006) , less than 2 teaspoons (2 ml) of methanol can cause blindness, and 2 table spoons (30 ml) can cause death. This toxicity is mainly due to it being converted in the body to formic acid and formaldehyde, which first attack the cells in the retina, then the other vital organs.
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Question: What is the relationship between pressure and temperature of a gas filled container with constant volume and number of moles?
Click on weblink 3.2 the simulation on the right will appear. In this simulation one can set the parameters as per desire. For this experiment we need to set the volume and number of moles constant. Three trials are done for accuracy. For the first trial, we need to set the volume constant. The volume will remain set to the default value. Then pump 100 heavy species particle in the container and keep them the same until the next trial. The temperature will automatically go to 300K, remove heat to lower the temperature to 150K.
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Research Question Will increasing the temperature (C) of the rennin enzyme affect the rate of reaction (seconds) at which Pauls full cream milk solidifies?
 Contrary, decreasing the temperature would slow down the speed of particle collision so therefore the rate of reaction will also decrease. In this experiment, the rate of the reaction of rennin and milk will be tested. The temperature of rennin will vary from 25�C, 30�C; 35�C; 40�C; 45�C and the rate (time) at which the rennin causes the milk to solidify will be recorded as results. As temperature is a important factor for this experiment, experiment will be carried out at standard lab conditions and with a constant 25�C air temperature.
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Research Question By measuring the pH value of the acetic acid using a pH meter at standard lab conditions, will increasing the concentration of the acid affect its experimental determined Ka and therefore its calculated pKa?
 pKa = -log Ka The pKa values of weaker acids will be larger than the values for stronger acids. Therefore the higher the pKa number is the weaker the acid. The concentration of an acid affects the Ka value and therefore the pKa value for a high molarity of any solution will attain a lower pH. With references to Ka, as the molarity of the solution increases the value of Ka decreases and the smaller Ka is the bigger pKa is.
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+ 5 I- (aq) + 6 H+ (aq) 3 I2 (aq) + 3 H20 (l) 2 S203 2- (aq) + I2 (aq) 2 I- (aq) + S406 2- (aq) The ratio of the Iodate to the Iodine is 1:3 And the ratio of the Thiosulfate to the Iodine is 1:2 Therefore, the ratio of the Thiosulfate to KIO3 is 6:1 In order to find moles of Thiosulfate, one must multiply the moles of KIO3(found earlier) by 6 = 0.00005 moles � 6 = 0.0003 moles of Thiosulfate In order to find the concentration of Thiosulfate, one must divide the number of moles by the volume from the average
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The time for the crucible to cool after each time being heat Leave the crucible on the wire gauze for approximately 2 minutes after heating. The heat energy given to the hydrated BaCl2 Leave the air hole half open for 5 minutes then open the air hole to heat the crucible strongly with the blue flame. Apparatus: _ Bunsen burner _ Digital balance _ Tongs _ Crucible with lid _ Spatula _ Tripod _ Lighter _ Clay triangle _ Wire gauze Material: _ Crystallized barium chloride Procedure: 1.
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Testing antacids. The purpose of this investigation is to test different antacids mild base that can neutralize acid - for their effectiveness in neutralizing stomach acids, to see if all antacid tablets are equally effective, and to learn the way of
Maalox 1.286g 0.200g 42 drops 2.8 ml 294 drops 14 ml/g 378 drops 18.004 ml Gaviscon 1.567g 0.200g 26 drops 1.5 ml 130 drops 6.5 ml/g 204 drops 10.1855 ml It is stated that pH of a normal stomach is about 1.5 which is very acidic. However, if the concentrations of acid in stomach are too high, it would cause great pain. A solution would be taking medication that contains an antacid, a mild base that can neutralize acid. With approximate mass of tablet of 0.200grams, it is to be mixed with water and thymol blue indicator which would change color at the pH level of around 2.
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Volume of Water in a cylinder B (mL � 0.1 mL) 0 10.0 5.0 1 9.7 5.3 2 9.4 5.5 3 9.2 5.8 4 9.0 6.1 5 8.8 6.2 6 8.7 6.3 7 8.5 6.4 8 8.4 6.6 9 8.3 6.7 10 8.2 6.8 11 8.1 7.0 12 7.9 7.1 13 7.8 7.2 14 7.7 7.3 15 7.6 7.4 16 7.5 7.5 17 7.5 7.5 18 7.5 7.5 19 7.5 7.5 Table 3. Reaching equilibrium in 10mL of water in cylinder A and B with the different radius straw with 10mL of water Number of Transfers Volume of Water in a cylinder A (mL � 0.1 mL)
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Determining the effect of the concentration of HCL over the rate of the reaction between Magnesium and Hydrochloric acid
* Cut the Mg ribbon into three different lengths of 1, 2 and 3cm. We will use different lengths of Mg to make more accurate the experiment as we will have the same three lengths for both of the concentrations used. * Clean the Mg ribbon with the sandpaper to remove any oxides * Prepare the chronometer, put the Mg ribbon inside the conical flask and put the cork. Start the chronometer * After the reaction has ended, record the volume of gas produced and the time taken to produce it.
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How the combustion of different types of food affect the amount of heat calories and energy yield emitted.
Furthermore, he expects that the most 'fatty' food will burn for a longer period of time, require less assistance, and will be more thoroughly burnt will less ash deposit remaining. The bread is expected to burn the least unassisted, the cracker the most, with the cereal in between the two values. This prediction is based on the chemical construction of the foods. The cracker has the least amount of air-pockets, contributing to the assumption that it will engulf in the flame with more ease.
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Then we recorded the final volume of water, and repeated the experiment until we had three trials. We concluded that the molar mass of butane can be determined through the average of repeated trials of the experiment were no systematic or random errors occur. DATA COLLECTION & PROCESSING (DCP) RAW DATA - Initial Mass of Lighter in (g +/- 0.01g) Final Mass of Lighter in (g +/- 0.01g) *Initial Volume of Water (mL +/- 0.1mL) *Final Volume of Water (mL +/- 0.1mL)
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Journals a. Analytical Chemistry: LC number: TP1. A53 Publisher: American Chemical Society Country published: USA Frequency: 2 times per month 1st issue owned: Volume 72, Number 1, Jan 2000 1st article in current issue: Volume 75, Number 24, December 2003 Title: On-Chip Hydrodynamic Chromatography Separation and Detection of Non-particles and Biomolecules. Authors: Marko T.Blon, Emil Chmela, R-Edwin Oosterbroek, Rob Tijssen, and Albert vanden Berg. Affiliation: MESA and Research Institute, University of Amsterdam b. Biochemistry: LC number: QP501. B54 Publisher: American Chemical Society Country published: USA Frequency: weekly (except for 1st week of January)
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Kinetics Lab. How does the molar concentration of hydrochloric acid affect the rate of pressure in a gas releasing reaction?
Total Time of Reaction 90 seconds in all trials Volume of Hydrochloric Acid 15cm3 in all trials Materials: * 250ml flask * 1-hole stopper with gas collection tube * 4.5 grams of sodium carbonate-deca-hydrate 0.5 for each trial (� 0.005g) * Explorer GLX with pressure sensor (�1.75kPa) * Laptop with Data Studio * Stop watch (� 0.005s) * 135ml of hydrochloric acid 45ml of each concentration (�1ml) * Balance Picture: Method: There will be three trials for each of the three different concentrations of hydrochloric acid.
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