International Baccalaureate: Chemistry
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545 International Baccalaureate Chemistry essays
- Peer Reviewed essays 1
2. While the water was heating, the mass of a clean, dry 50-mL beaker was determined and recorded. Between 80 g and 120 g of lead shot was then added to the beaker and their combined mass was measured and recorded. 3. The lead shot was then transferred to a large, dry test tube. The utility clamp was used to suspend the test tube in the boiling water; the lead shot was below the level of the water in the beaker. The test tube was then left in the boiling for 10 minutes. 4. While the lead shot was heating, 100 mL of distilled water was measured I na graduated cylinder.
- Essay length: 583 words
Investigating Stoichiometry - The table shows the mass of reactants potassium iodide and lead(II) nitrate, and the mass of the precipitate from the reaction
Some of the mixture was stuck in the beaker even after trying to wash it down water and scooping it out with the glass rod. 3) After filtrating the mixture, it was observed that there were some parts of the filtrate that was still yellow in colour, with some PbI2 crystals floating around, which meant that some of the residue (PbI2) passed through the filter paper. Even so, another round of filtration was not carried out. The chemical equation obtained from the reaction above: 2KI(aq) + Pb(NO3)2(aq) --> 2KNO3(aq) + PbI2(s) Step 1) Using stoichiometry, predict the mass of PbI2(s)
- Essay length: 964 words
The purpose of this investigation is to determine the effect varying temperatures have on the rate of reaction of magnesium (Mg) reacting with hydrochloric acid (HCl).
(calculated by getting mass of magnesium strip and converting it into moles) by the time taken for reaction to complete (when magnesium strip is completely used up). Controlled: * Length of Magnesium (Mg) Strip o 1.1 cm of magnesium strip will be used for all trials. The length of the magnesium strip will be measured accurately using a ruler (±0.05cm) * Amount of Hydrochloric acid solution (HCl) o 16mL of hydrochloric acid solution will be used for all trials. The volume will be measured accurately using a graduated cylinder (±0.5mL) * Concentration of the Hydrochloric acid solution o 3.0M of Hydrochloric acid will be used for all trials (the 3.0M solution is pre-made)
- Essay length: 2033 words
The purpose of this lab experiment is to determine whether different ionic compounds containing sodium in ethanol will affect its evaporation rate
compound being attracted to the multiple hydrogens in an ethanol molecule; meaning that it will have a less steep slope than the other ionic compounds. Also, the ethanol by itself will most likely have the highest rate of evaporation because on itself it evaporates extremely quickly into the air, and it would probably show the steepest slope on the Logger Pro graph. Materials: 1. Erlenmeyer flask 2. Graduated cylinder 3. Pure ethanol C2H6O (10.0 mL per trial) 4. Gas pressure sensor a. Probe, computer and Vernier's Logger Pro 5. Computer a. Vernier's Logger Pro 6. Weigh boats 7. Balance 8.
- Essay length: 1654 words
Despite this it was possible to make some observations as to why the particular trial conducted by the experimenters' one particular trial, varied from the other results while making speculations as to why some of the other trials had certain results. It was observed that the groups were having difficulty determine whence the colour change had taken place. The time of colour change were often disputed between the student group members indicating the effect of human error. Other observations included that of the gradual colour change of the iodine prior to being added with the Propanone.
- Essay length: 5047 words
Acids/Bases Design Lab. How does a change in the pH value of a solution of hydrochloric acid (HCl(aq)), affect how much zinc metal is reacted with the hydrochloric acid in a one minute time frame
Of course, a change of pH by one decimal means a 10-fold change in the concentration of the acid being used, as can also be observed by the above table, where the concentration of hydrochloric acid is being decreased by 1/10th except when the concentration is at 2.0 mol dm-3, in which case this was solely being done to observe the effects of negative pH values for a more complete and observable trend. Therefore, the independent variable will be manipulated by varying the concentration of hydrochloric acid solutions used, and as such, vary the pH values.
- Essay length: 4932 words
Enthalpy Change Design Lab (6/6)How does changing the initial temperature (19C, 25C, 35C, and 45C) of two 40.0 cm3 at 1.00 mol dm-3 solutions of KOH(aq) and HCl(aq) affect the molar enthalpy change of the neutralization reaction
Then, to achieve higher temperatures for the reactants, 40.0 cm3 of both the 1.00 mol dm-3 HCl(aq) and 1.00 mol dm-3 will be measured out using a 50.0 cm3 +/- 0.5 graduated cylinder, and poured into separate 150 cm3 clean, dry glass beakers. These two beakers will then be placed on the same electrically powered hotplate, which is set to medium-high heat. The temperatures will be monitored with separate Vernier temperature probes, connected to a Vernier LabQuest with LoggerPro Data collection software. If one of the 150 cm3 beakers containing 40.0 cm3 of either 1.00 mol dm-3 KOH(aq)
- Essay length: 4925 words
Hydrogen Gas Collection Lab CE (6/6) A sample of solid magnesium ribbon, measuring approximately 2.5cm and weighing 0.037 g +/- 3% was allowed to react with an aqueous solution of hydrochloric acid
that the number of moles of hydrogen gas collected in the gas measuring tube were 0.00156 mol +/- 2%, as calculated in the data processing section of the investigation report. To determine the percentage yield of hydrogen gas in the reaction between 14.90 cm3 +/- 0.3% of 6 mol dm-3 HCl(aq) and 0.0015 mol +/- 3% of Mg(s), the following equation is applied: Percentage actual yield of hydrogen gas x 100 yield of = theoretical yield of hydrogen gas hydrogen gas = 0.00156 mol x 100 0.0015 mol = 104% Therefore, it can be said that that 4% too much hydrogen gas was collected during the investigation regarding the reaction between 14.90 cm3 +/- 0.3% of 6 mol dm-3 HCl(aq)
- Essay length: 3897 words
The aim of the experiment is determining the percentage yield of the product (copper), in the reaction of copper chloride with aluminum
and aluminum (Al); and the products of the reaction are: aluminum chloride (AlCl3) and copper (Cu). The equation before balancing: CuCl2 + Al AlCl3 + Cu The equation when balanced: 3CuCl2 + 2Al 2AlCl3 + 3Cu The research question is to find out the percentage yield of copper. So, the first step is to figure out the theoretical yield of Cu (it doesn't need to be 3Cu, because both sides of the equation are balanced, so it doesn't make any difference). > In order to find the theoretical yield of Cu, the first step is to know the theoretical yield of CuCl2 (which is 2.00 grams)
- Essay length: 1276 words
Temperature of flame Controlled Variable A blue flame will be used in all cases, using the same burner with the air hole completely open. Apparatus and Materials * Crucible and lid (1) * Mg ribbon (1) * Tripod stand (1) * Bunsen Burner (1) * Crucible tongs (1) * Clay triangle (1) * ±0.001g Electronic scale (1) Safety Aspects Safety Concern Risk Precaution MSDS reference Burning magnesium Eye damage Do not look at the burning Mg for prolonged periods of time.
- Essay length: 2695 words
trial, as it is pre-measured Amount of the calcium carbonate in each trial The more calcium carbonates in HCl, the faster the reaction. As in this case, we intentionally designed CaCO3 to be the limiting reagent, an increase/decrease in the particle would cause a change in the amount of products. Use an electronic balance to measure 0.6 g of calcium carbonate in every trials The time we used to set perform the experiment Plays a major on how the experiment is being conduct, with out this control the average of all the trials would be different and that in the
- Essay length: 1913 words
Electrochemical cells - investigate the effect of the temperature change of the anode electrolyte has on the average voltage produced by a voltaic cell with 50ml of 0.5M Zinc sulphate solution and 50ml of 0.5M Magnesium sulphate solution.
Mg strip in each repeated experiment Size of cathode Cut the same size of Zn strip in each repeated experiment Size of beakers Using the 100ml of beakers in the experiments Concentration of salt bridge electrolyte Using the same concentration (4M) of KNO3 in each experiment. Length of salt bridge Use the same length (3cmx10cm) of salt bridge Width of salt bridge Use the same width (1cm) of salt bridge Electrode immersion depth Use clamp to stable the electrode and make their immersion depth are the same.
- Essay length: 2256 words
The Objective of this lab is to experimentally determine the molar mass of an unknown and volatile liquid.
The empty flat bottom flask was weighed and then the unknown liquid was poured into it. 5. The 1 liter beaker was placed on the hot plate and filled with enough water to submerge the flat bottom flask. 6. Supported by a buret clap attached to the ring stand, the flat bottom flask was lowered into the beaker. 7. The thermometer was also lowered into the beaker.
- Essay length: 524 words
Can one determine the coefficients of a balanced chemical equation by having the mass of a reagent, the mass of the dry product and by using stoichiometry?
Hence finding the balanced chemical equation of the reaction. Procedure 1. Before the experiment is performed, two data tables are constructed. This is crucial because the time in the lab must be used efficiently, and time cannot be wasted in creating data tables which must be used for recording qualitative and quantitative observations. Data tables should resemble the ones outlined below. 2. Take a 2.50g strip of aluminum and make sure that it is shined so that any oxidized aluminum is removed. Any oxidized aluminum could interfere with the precision as well as the accuracy of the mass of the aluminum.
- Essay length: 3084 words
Airbag design lab. Is it possible to use baking soda, NaHCO3(s), and 2.00 mol dm-3 HCl(aq) to generate a gas that will fill a zip-lock bag and act as an air bag?
In order for the reaction to take place only when needed, the baking soda will rest in the Ziploc bag while the hydrochloric acid will be added when needed. In order to determine the amount of reactants needed, the volume of the ziploc bag where the reaction will take place to create an airbag must be known. The ziploc bag will first be filled with water then dumped into a graduated cylinder in order to determine the volume of the bag.
- Essay length: 1565 words
The purpose of this lab was to observe chemical changes, to write balanced equations, and to identify different types of reactions.
* Reaction 2: Reaction between cobalt (II) chloride solution and sodium hydroxide solution. Materials: small beaker, cobalt (II) chloride solution and sodium hydroxide solution 1. Place 10 ml of cobalt (II) chloride solution into a small beaker. 2. Record observation. 3. Add the same amount of sodium hydroxide to the cobalt (II) chloride solution. 4. Record all observations in the Data Collection Table. 5. Clean Up: Pour the contents of the beaker into the collecting reservoir. * Reaction 3: Combustion of magnesium ribbon. Materials: tongs, Bunsen burner, matches and a small strip of magnesium ribbon 1.
- Essay length: 894 words
The temperature of the exhaust is high because of the heat that is transferred to the exhaust during combustion. Because of the high temperatures, oxides usually occur as a gas, but there can be liquid or solid exhaust products as well. Heat is also released as a result of burning. Burning comes out in the form of either a glow or flames, appearance of light flickering. You can make this chemical reaction by rubbing two sticks together. It is because the fuel is usually a hydrocarbon, an organic compound made entirely of carbon and hydrogen, and sticks work perfectly well for that.
- Essay length: 1121 words
* The test tube went darker. * There was water which evaporate from the sample of copper sulfate. * There was condensed vapor which are formed on the test tube wall. Data processing: Measurements Mass (gram) First Second Third Mass of hydrated salt 0.6 0.8 1.1 Mass of anhydrous salt 0.4 0.6 0.1 Mass of water lost 0.2 0.2 1.0 Mole of CuSO4(mol) 0.0025 0.0037 0.0006 Mole of H2O (mol) 0.0111 0.0111 0.0555 Mole of H2Oin each mole of CuSO4(mol) 4 3 92.5 Example of calculation ( data from first measurement): Mass of hydrated salt = (Mass of the test tube + hydrated salt)
- Essay length: 644 words
Apparatus: * Standard Thermometer * 1 M HCl * Magnesium Oxide (MgO) * Magnesium Ribbon (Mg) * Probe (GLX) * Graduated Cylinder (100 ml) * Beaker (250 ml) * Styrofoam Cup X 2 Method: A Styrofoam cup was set up and placed in a beaker. 50 ml of I M HCl was measured and poured into a Styrofoam cup. A temperature probe was placed in hole at the top of cup and the initial temperature was recorded. 0.25 g Magnesium was added to the solution. Temperature was recorded until the trend stabilized.
- Essay length: 881 words
(2 pairs) A/D and B/C B) How will elements A and D compare in terms of chemical/physical properties? as they are the same element, their chemical properties will be identical (although since element A has lost electrons to become the B3+ ion, it has already achieved noble gas configuration and will be inert). With different amounts of neutrons, and thus different masses, elements A and D will show different physical properties (like density, diffusion rate, etc.) C) How will elements A and D compare in terms of atomic mass? A will have a higher mass (11 vs. 10)
- Essay length: 2151 words
Weighed the Zn solid. 7. Weighed a piece of filter paper, then placed into a glass funnel over a beaker (see Figure 1) to create a filter system. Figure 1 8. Poured solution bearing precipitated Cu into the filter system. Rinsed beaker with a small amount of 1.0M HCl to remove any remaining bits of Cu and poured solution into filter. 9. Rinsed precipitate in filter with distilled H20. 10. Rinsed precipitate in filter with 70% isopropyl alcohol in order to remove any remaining H20.
- Essay length: 1229 words
3. Control: Volume (ml) and concentration (M) of HCl and Na2S2O3. * Procedure: a) Transfer 50 ml 0.0400 M sodium thiosulfate solution into a 50 ml flask. b) With a marker make a black cross in a paper and put it below the flask. c) At room temperature quickly pour 5ml HCl of a 2M solution d) Measure the time needed for the black cross to disappeared. e) Repeat this procedure and then place the flask in a hot plate using a thermometer and vary the temperature to 30 °C, 40 °C, 50 °C and 60 °C.
- Essay length: 487 words
: Effect of heat hydrated copper (II) sulphate and subsequent addition of water to the anhydrous product.
Le Châtelier's Principle states that the system will react to remove the added heat, thus the reaction must proceed in the reverse direction: This is an endothermic reaction. Then we added water to the test tube that contains hydrated copper (II) sulphate and it turned blue again. The equilibrium shift to the right because the temperature was decrease. Because the reaction is exothermic, the reaction produces heat when it proceeds in the forward direction.
- Essay length: 442 words
increasing mass of CaCO3 c. decreasing size of CaCO3 particles d. decreasing amount of CO2 present e. increasing temperature f. adding water to the reaction g. removing water from the reaction vessel h. adding a catalyst 16. Explain, using the Maxwell-Boltzmann Energy distribution, why adding a catalyst increases reaction rate. 17. Determine the rate law for the following reaction A + 2B --> AB2 A (molarity) B (molarity) Rate (M/s) 2 2 5 2 4 10 4 4 40 18. Using the data from the previous problem, calculate the rate constant 19. What would the rate be if the [A] = 2.5 mol dm-3 and [B] = 3.0 mol dm-3?
- Essay length: 3114 words
* Electromagnetic radiation comes in packages called quanta or photons. Atomic Emission Spectra * White light is made up of all the colours of the spectra. * When it passes through a prism a continuous spectrum is obtained. * When energy is applied to specific (individual) elements they emit a spectrum which only contains emissions of particular s. * A line spectrum is not continuous. Each element has its own characteristic line spectrum. * Hydrogen spectrum- it consists of discrete lines that converge towards the high energy end of the spectrum.
- Essay length: 8274 words