Introduction:
In this experiment acid base indicators will be tested, using a red cabbage mixture. Substances can be classified as acidic or alkalinic depending on the concentration of hydrogen or hydroxide ions. The higher the concentration of hydrogen ions the lower the pH this means it will be an acid and the higher the concentration of hydroxide ions the higher the pH this means it will be an base(science prof online). A pH indicator is a solution or mixture that changes colour in the presence of an acid or base. Red cabbage contains a specific pigment called flavin(science kiddo), in acidic conditions this pigment will turn a red colour and in basic conditions it will turn a green colour. From this it is noticeable that the colour change
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In the experiment the lemon juice tested to be the strongest acid with a pH of 2 and the pink colour change, the weakest acid was ENO antacid tablets with a pH of 6.1 accompanied by a violet colour change. . In the experiment the Handy Andy or ammonia tested to be the strongest base with a pH of 11.6 and a green colour change, the weakest base was baking powder with a pH of 8 accompanied by a blue-ish purple colour change. And it was also tested that water was slightly acidic with a pH of 7.2. An acid is considered to be a proton donor, this means it dissociates into hydrogen ions in a solution (Wikipedia), this will correspond to it having a sour taste and sharp odour. A base is considered to be a proton accepter, this means it dissociates into hydroxide ions in a solution (Wikipedia), this will correspond to it having a bitter taste and no scent. Acids add more hydrogen ions to a solution, while bases remove hydrogen ions from a solution, so the pH can be adjusted to any value wanted by carefully combining acids and bases together, if a vinegar solution that is strongly acidic is present, the pH can be raised by slowing adding a base like ammonia which will remove some of the extra hydrogen ions from the solution. If just a little was added the pH might change from 2 to 5, making a weaker acid, but by adding a little more base enough hydrogen ions is removed to raise the pH to 7 or neutralize the solution, also by adding even more base more hydrogen ions can be removed, raising the pH until the solution becomes a strong base (Coolscience). Experiments are replicated too ensure accurate results and to verify uncertain results it also helps to refine experimental observations (ochemonline). The most common pH testing in laboratories is a device called a probe and meter, commonly
The last test was called the Acidity test. The Acidity test gives us the alkalinity and acid of a stream. On the Ph scale it goes from 0 to 14. A stream with a great abundance of life will probably have a reading of 7 on the scale( which is near neutral). Here are the results from some of the tests.
The lab started off by measuring critical materials for the lab: the mass of an an empty 100 mL beaker, mass of beaker and copper chloride together(52.30 g), and the mass of three iron nails(2.73 g). The goal of this experiment is to determine the number of moles of copper and iron that would be produced in the reaction of iron and copper(II) chloride, the ratio of moles of iron to moles of copper, and the percent yield of copper produced. 2.00 grams of copper(II) chloride was added in the beaker to mix with 15 mL of distilled water. Then, three dry nails are placed in the copper(II) chloride solution for approximately 25 minutes. The three nails have to be scraped clean by sandpaper to make the surface of the nail shiny; if the nails are not clean, then some unknown substances might accidentally mix into the reaction and cause variations of the result.
Elijah Brycth B. Jarlos IX-Argon 1. Multicellularity is a condition of an organism to have multicellular cells. An example of a organism who has multicellular cells are plants, animals, and humans. The main reason of why scientists have a hard time finding a good set of existing organisms to compare. Is neither the first set of organisms which is being compared is dying as fast as the second specimen is being examined or they just can’t find the right species.
I organized four different tests; pH paper, alkalinity tests, the number of rocks neutralizing acid, and the number of rocks that don’t neutralize acid. The average for pH paper was seven. The pH is the numeric scale used to specify the acidity or alkalinity of an aqueous solution. The pH scale measures acidity and alkalinity. the pH scale goes from zero, which is an acid reading, to fourteen, which is an alkaline reading.
CLAIRE MUNTING 29/01/2018 Criterion C EFFECTS OF SURFACE AREA OF CALCIUM CARBONATE UPON RATE OF REACTION Calcium Carbonate Chips 1 Introduction: Within the current investigation, the effects of the surface area of Calcium Carbonate (CaCO3) in combination with Hydrochloric acid (HCl) upon its rate of reaction. CaCO3, commonly referred to as limestone, is an organic substance and is, in a sense, the crystallised “carbonic salt” of the element, calcium2. In addition to being a salt, the pH level of Calcium Carbonate is 9.91, and it is therefore, a basic substance, due to the fact that it is comprised of a pH level higher than 7, which is neutral3. HCl, however, is the bodily acid found in the stomach of human beings.
Properties of Substances Express Lab 1)The purpose of this lab was to compare the physical properties of different types of solids and how the properties of solids are determined by their intermolecular forces and their intramolecular bonds. Then we were to classify each type of solid as either ionic, metallic, non-polar molecular, polar molecular, or network. Paraffin wax classified as a non-polar molecular, Silicon dioxide was classifies as a network, Sodium chloride was classified as ionic, Sucrose was classified as polar molecular and Tin was classified as metallic. (2)The intermolecular forces that are present in Paraffin wax are dispersion forces, because it is non-polar and carries a negative charge. Followed by Sucrose that has
Two of the same types of plants were used, in order for the results to be reliable. One of the plants was labelled DISTILLED whereas the other was ACIDIC, so the results don’t get mixed. The DISTILLED plant was used as a controlled variable, where normal spring water was used (pH 7.3) The ACIDIC plant was the one the experiment had taken place on, this was where lemon water was used (pH 2.0) Throughout the experiment pictures were taken, so one will be able to notice the colour change on the acidic plants, as it had started to slowly die. With both plants you are able to notice that they had both started to grow flowers, but more the spring watered plant than that on the lemon juice watered one. The results of the plant growth was recorded to we would be able to notice the amount it had grown, this would be the water compared to lemon juice.
The equation of the reaction between sodium hydroxide and ethanoic acid is as follows: CH3COOH + NaOH → CH3COONa + H2O We can measure the end point of titration process and we can also measure the amount of reactants. The concentration of ethanoic acid in the vinegar can be determined through stoichiometric calculations, Using the values obtained from the titration, and also the chemical equation as a reference. Phenolphthalein indicator is used in this acid-base titration Equipment and materials:
Acids are proton donors in chemical reactions which increase the number of hydrogen ions in a solution while bases are proton acceptors in reactions which reduce the number of hydrogen ions in a solution. Therefore, an acidic solution has more hydrogen ions than a basic solution; and basic solution has more hydroxide ions than an acidic solution. Acid substances taste sour. They have a pH lower than 7 and turns blue litmus paper into red. Meanwhile, bases are slippery and taste bitter.
The 3 concentrations of enzymes were 0.5 ml, 1.0 ml, and 2.0 ml of turnip extract, while the substrate consisted of 0.1ml, 0.2 ml, and 0.4 ml of hydrogen peroxide. In a separate tube, the control was made up of turnip extract and guaiacol, known as the color reagent. This was recorded the absorbance every 20 seconds for 3 minutes.
Strong acids and strong bases are strong electrolytes and are assumed to ionize completely in the presence of water. Weak acids however, only ionize to a limited extend in water. Any weak or strong acids when in contact with any weak or strong alkali will start to undergo neutralization regardless of their volume. When an indicator which is present in the acid-base mixture and have experienced colour change, it indicates that the mixture is in right proportions to neutralize each other and is also known as the equivalence point.
When carbohydrate is utilized, acids are formed which changes the colour of the medium from green to yellow
Introduction Buffer is a solution that resists a change in pH when bases or acid are added. Solutions that are acidic contain high concentrations of hydrogen ions (H+) and have pH values less than seven. Buffer usually consist of a weak acid, and its conjugate base or a weak base and its conjugate acid. The function of buffer is to resist the changes in hydrogen ion concentration as a result of internal and environmental factor. This buffer experiment is important so that we relies the important of buffer in our life.
Introduction The goal of the experiment is to examine how the rate of reaction between Hydrochloric acid and Sodium thiosulphate is affected by altering the concentrations. The concentration of Sodium thiosulfate will be altered by adding deionised water and decreasing the amount of Sodium thiosulphate. Once the Sodium thiosulphate has been tested several times. The effect of concentration on the rate of reaction can be examined in this experiment.
Abstract The unknown concentration of benzoic acid used when titrated with standardized 0.1031M NaOH and the solubility was calculated at two different temperatures (20◦C and 30◦C). With the aid of the Van’t Hoff equation, the enthalpy of solution of benzoic acid at those temperatures was determined as 10.82 KJ. This compares well with the value of 10.27KJ found in the literature.