#### Determination of the % by volume of ethanoic acid in 100cm^3 of water

I.B. CHEMISTRY: PRACTICAL 08-12-12. P2,P3,& P4-STOICHIOMETRY SULAIMAN JALLOH AIM: 1) To prepare a standard solution of potassium hydrogen phthalate by weighing and dissolving it water of correct volume. 2)To use the standard solution of 1) to standardize(find the concentration of) sodium hydroxide solution. 3)To determine the percentage of ethanoic acid,by volume,in vinegar,by titrating with standardized sodium hydroxide in 2) ) MAKING A STANDARD SOLUTION OF POTASSIUM HYDROGEN PHTHALATE RAW DATA TABLE mass of weighing bottle,m+/-0.01g Volume of solution titrated,v+/-0.15 Concentration of sodium hydroxide given ,Cb/mol/ 33.88 250.00 0.1 The purity of the acid is given as 99.5+/-0.5% Calculations for the mass of the acid needed to make 250 of solution of the acid. Equation for the reaction: C6H5COOKCOOH+NaOH C6H5COOKCOONa+H2O so,the mole ratio of the acid to base is 1:1 This means 1 mole of acid gives 1 mole of the base. number of moles of sodium hydroxide,Nb=c v where c=concentration of sodium hydroxide v=volume of solution titrated Nb=0.1 250/1000) Nb=0.0250moles Hence the number of moles of the acid will be 0.0250 moles since the mole ratio is 1:1 number of moles of acid,Na=mass of the acid/molar mass of the acid mass of the acid,Ma=molar mass of the acid number of moles of the acid molar mass of the

• Word count: 2311
• Level: International Baccalaureate
• Subject: Chemistry

#### Titration lab report. Aim: to determine the quantity and concentration of NaOH to completely neutralize one molar hydrochloric acid till the n point.

Practical Report-3 Titration ________________ Aim: to determine the quantity and concentration of NaOH to completely neutralize one molar hydrochloric acid till the n point. Requirements: hydrochloric acid 0.5 mole, sodium hydroxide , pipette, pipette pump, conical flask, burette, stand, clamp, plastic funnel, beaker, phenolphthalein Hypothesis: the indicator is used to display the pH of the solution. It will display different colour in different acid and different in base. In this case when the pH of the solution increases and as soon as is crosses 7 the colour will change this will allow us to know the approximate amount of base (NaOH) required of neutralize acid (0.5 molar HCl). From the results we would know the quantity required to neutralize the acid also the quantity can be used to calculate the concentration of NaOH. Control Variable Dependant variable Independent variable 1. Concentration of HCl and NaOH 2. Temperature 3. Pressure 4. pH of HCl 1. Volume of NaOH 1. colour of HCl Method: arrange burette, stand and clamp in the following way and place the conical flask . Using a pipette and a pipette pump take 20 ml of HCl in the conical flask 2. Add few drops of phenoptheline to acid 3. Add NaOH in the burette till the 0 level 4. Slowly add NaOH to HCl 5. Stir the solution after adding every drop till the solution changes the colour Observations:

• Word count: 434
• Level: International Baccalaureate
• Subject: Chemistry

#### Energy Change in a chemical reaction. Throughout this investigation I will try to figure out the energy difference between different compounds reacting with water in a solution while it is being heated up.

Chemistry Lab report Gordon Ho Energy Change in a Chemical Reaction Introduction Throughout this investigation I will try to figure out the energy difference between different compounds reacting with water in a solution while it is being heated up. The experiment that was conducted to find a difference between solutions such as hydrochloric acid and water and compare it a regular water solution to examine the factors of that would produce an energy change between the two solutions. I hypothesize that since magnesium and hydrochloric acid will react heavily and the resulting solution will be of a lower boiling and melting point so therefore it will take longer for the solution to boil. I also hypothesize that the solution with the water and magnesium will accelerate the energy change while heated up as magnesium is a highly reactive metal and will cause a reaction at an increased temperature and cause particles within the solution to speed up and increasing the temperature. Variables Independent Variables Temperature (This variable was controlled to keep the three separate experiments valid as the experiment was conducted to figure out the factors that affected the rate of which energy is transferred through a reaction so this variable must be kept equal. Dependent Variable Time (This variable was dependant on the temperature as it was one of the factors that was

• Word count: 773
• Level: International Baccalaureate
• Subject: Chemistry

#### Percent Yield Lab. This experiment has proven that KI is the limiting reagent in this chemical reaction.

Percent Yield Lab Introduction When a chemical reaction occurs and two reactants mix, we should in theory be able to determine the amount of each product formed using stoichiometric calculations. The maximum value of the final product is limited to the limiting reagent not the reagent in excess. From determining the limiting reagent we are able to calculate the theoretical mass of the product formed. First step to find the percentage yield is to balance. The number of atoms in the reactants must be equal to the atoms in the products. This is due to the law of conservation of mass. Matter can’t be destroyed or created but transferred so therefore the chemical equation has to be balance so that the number of atoms on both side and the exact ratio of how the reactants is displayed. Second step is to find the limiting reagent. Limiting reagent is the reactant that is depended upon to determine how much of product is made. In order to find the limiting reagent the equation moles= mass/molar mass. Now that the moles are figured out, multiply the number of moles of the reactants by the ratio of the reactant and the product. This calculation is performed twice once for the first reactant and one for the second. Then the Theoretical Yield is calculated, it is how much product will be synthesized with the reactants. Multiply the lowest number of moles (limiting reagent’s mole)

• Word count: 1671
• Level: International Baccalaureate
• Subject: Chemistry

#### Effect of temperature on pH of water samples

Lab on effect of temperature on pH of water Lab type: DCP & CE/DCE. Theory: Water contains both hydrogen ions, H+, and hydroxide ions, OH–. The relative concentrations of these two ions determine the pH value.1 Water with a pH of 7 has equal concentrations of these two ions and is considered to be a neutral solution. If a solution is acidic, the concentration of H+ ions exceeds that of the OH– ions. In a basic solution, the concentration of OH– ions exceeds that of the H+ ions. On a pH scale of 0 to 14, a value of 0 is the most acidic, and 14 the most basic. A change from pH 7 to pH 8 in a lake or stream represents a ten-fold increase in the OH– ion concentration. Rainfall generally has a pH value Between 5 and 6.5. It is acidic because of dissolved carbon dioxide and air pollutants, such as sulfur dioxide or nitrogen oxides. If the rainwater flows over soil containing hard-water minerals, its pH usually increases. Bicarbonate ions, HCO3–, resulting from limestone deposits react with the water to produce OH– ions, according to the equation: HCO3– + H2O → H2CO3 + OH– As a result, streams and lakes are often basic, with pH values between 7 and 8, sometimes as high as 8.5. The measure of the pH of a body of water is very important as an indication of water quality, because of the sensitivity of aquatic organisms to the pH of their

• Word count: 1670
• Level: International Baccalaureate
• Subject: Chemistry

#### Organic lab. Comparison of alkanes and alkenes

Vita Salvioni Guttmann Chemistry III HL 22-10-2012 Organic Lab Data Collection Part I – Alkanes . Volatility of methane, hexane, and paraffin Substance Methane Hexane Paraffin wax Observations Colorless gas, with a smell of sweet burnt alcohol. Clear, colorless liquid. Alcoholic smell, light but pungent. White, oily (waxy) solid. Very malleable, odorless. . Solubility of hexane and paraffin in water Substance Hexane + water Paraffin wax + water Observations Hexane when shaken with water does not dissolve. We can tell so because even though both liquids are clear and colorless, we can see a clear line which distinguishes one liquid from the other. The hexane floats right above the water, never mixing, and we can see the line of separation. Paraffin wax when shaken with water also does not dissolve. Even when finely ground, the solid pieces of wax float throughout the liquid and eventually deposit on the bottom of the test tube, never mixing with the water. . Combustibility of methane, hexane, and paraffin wax Substance Methane Hexane Paraffin wax Observations When the lighted splint is inserted in the test tube filled with methane, the flame quickly extinguishes itself, with a small spurt of black smoke. Right after, water vapour coats the walls of the test tube. Therefore, combustion occurred, since the water vapour means that H2O and CO2

• Word count: 2623
• Level: International Baccalaureate
• Subject: Chemistry

#### Experiment to investigate the effect of concentration of electrolyte on the current of voltaic cell

Experiment to investigate the effect of concentration of electrolyte on the current of voltaic cell Aim The aim is to identify the relationship between the concentration of H2SO4 solution and the current of Cu-Zn voltaic cell. Hypothesis My hypothesis is that the greater the concentration of sulfuric acid the bigger the current of the voltaic cell. In a voltaic cell, chemical energy is concerted to electrical though the oxidation and reduction happen on the electrodes. Current will not flow through pure water. There must be electrolytes dissolved in it before electricity can pass through it. When the concentration of sulfuric acid is increased, the number of ions is increased. There will be more ion carrying electric charge. Then, current is increased. Introduction and Background This is the Cu-Zn voltaic cell used in the experiment. Zinc has higher reactivity and it is more likely to loss electrons. Thus, electrons flow from Zn electrode to Cu electrode. Copper stripe is the positive electrode. Zinc stripe is the negative electrode. Reaction happened on each terminal: Positive terminal: Zn-2e-Zn2+ Negative terminal: 2H2e-H2 It is assumed that bubbles (hydrogen gas) will come out from copper electrode. It is assumed that zinc and copper stripes are pure. Classification of variables Dependent variables Current of the voltaic cell Independent variables

• Word count: 907
• Level: International Baccalaureate
• Subject: Chemistry

#### Chemistry thermo lab, Hess's Law.

________________ ________________ ________________ ________________ ________________ Hess’s Law Lab ________________ Qusai Al Omari ________________ Introduction: In this lab, we will be determining the change in enthalpy for the combustion reaction of magnesium (Mg) using Hess’s law. Procedure: . React about 100 mL of 1.00 M hydrochloric acid with 0.80 g of MgO. Note the change in temperature and any qualitative data. 2. React about 100 mL of 1.00 M hydrochloric acid with 0.50 g of Mg. Note the change in temperature and any qualitative data. Raw Data: Quantitative: Reaction, trial Mass (± 0.01 g) Initial temperature (± 0.1⁰ C) Final temperature (± 0.1⁰ C) Volume of HCl (± 0.05 mL) Reaction 1, Trial 1 0.80 22.0 26.9 100.00 Reaction 1, Trial 2 0.80 22.2 26.9 100.00 Reaction 2, Trial 1 0.50 21.6 44.4 100.00 Reaction 2, Trial 2 0.50 21.8 43.8 100.00 Qualitative: . Hydrochloric acid is colorless and odorless 2. Magnesium tape is shiny after cleaning it from oxidants, increasing its purity. 3. In both reactions, the solution became bubbly. 4. There was a strong odor from the reaction. Data Processing: Trial 1: Reaction 1: First, we have to calculate the ΔT by subtracting the final temperature by initial temperature: . 2. 3. Now we calculate the mass of the solution, assuming it has the density as water: 1. 2.

• Word count: 11607
• Level: International Baccalaureate
• Subject: Chemistry

#### Which fruit juice (Orange, Apple, Peach, Pineapple, and Apricot) has the highest concentration of ascorbic acid?

Dafna Bicaci IB Chemistry SL Acids & Bases - Design Lab ASCORBID ACID CONTENT DESIGN LAB PURPOSE: Which fruit juice (Orange, Apple, Peach, Pineapple, and Apricot) has the highest concentration of ascorbic acid? VARIABLES: . Independent Variables: In this experiment, my independent variables are the different fruit juices; apple, apricot, peach, orange and pineapple. 2. Dependent Variables: The dependent variable in this experiment is the concentration of ascorbic acid the fruit juice contains which is calculated by the formula: , in this case, (Concentration(DCPIP) x Volume(DCPIP))/ Volume(Ascorbic Acid) = C(Ascorbic Acid) 3. Controlled Variables: 1. I will use the same brand of fruit juice for every trial 2. The juices will be diluted with 10 mL distilled water. 3. I will use 0.1 mol/dm3 of DCPIP for each trial. MATERIALS: 1. 30 mL each of ‘Tamek’ brand Apple Juice, Orange Juice, Pineapple Juice, Apricot Juice, and Peach Juice 2. Graduated cylinder 3. 100 milliliters of dichlorophenolindophenol (DCPIP) indicator solution 4. Burette 5. Distilled water 6. Funnel 7. Conical flask 8. Beakers PROCEDURE: 1. Gather your materials. 2. Set Burette onto stand with clamp. 3. Fill a graduated cylinder with 10 mL of distilled water and pour into a beaker. 4. Fill a graduated cylinder with 10 mL of Apple Juice and pour into the beaker with

• Word count: 1091
• Level: International Baccalaureate
• Subject: Chemistry

#### The Importance of the Science of Chemistry

Chemistry is the branch of science that deals with the structure of organic and inorganic matter( any substance or organism which has a mass and occupies space), its properties and reactions; however chemistry is primarily the study of reactions that any given substance takes on when interacting with another substance. Chemistry is the main incentive for the life that we live today; it has provided modern society with facilities that make our day to day lives easier. Predominantly chemistry has allowed us to understand the composition of the world. In short this branch of science has enabled us to lead a better quality of life. The first ever study of chemistry can be tracked back to the days of alchemy. Alchemy is an ancient and philosophical study of chemistry, the subject ranged from ancient Egypt to Islamic empires. Alchemists were the first researchers to discover elements, however today their work has been labelled as wrong, meaningless and inventions of the mind. It is an entrenched theory that alchemists believed that lead could be turned into gold and that earth was composed of only four elements, air, water, earth and fire. Alchemists were uneducated, and in simple fruitcakes, but this in fact would be to give a negative image. They did not have to ability than to investigate and speculate the hows and whys, and any chemical reaction was believed to be a magical

• Word count: 1993
• Level: International Baccalaureate
• Subject: Chemistry