Bases and Alkalis A base is a compound that reacts with and neutralises an acid. The reaction forms a salt plus water. Alkalis are a type of base - ones that dissolve in water. Alkalis are compounds that react and neutralise acids. Like bases, they form a salt and water in the reaction. Alkalis turn red litmus indicator paper blue and they cause Universal Indicator paper to turn blue or purple. Alkaline solutions have a pH value greater than 7. Alkaline solutions feel soapy and are
changing the concentration of an alkali, on the volume of acid needed to neutralise it, when acid is added to it? The plan is to use two acids (Hydrochloric & Sulphuric) and one alkali (Sodium Hydroxide). The reason I need to use two acids is; because the question applies to all acids and alkalis and to just use one of each would not enable me to come to a general conclusion. If there had been more time available, ideally I would have preferred to use two alkalis as well as two acids. Predictions
Investigating Temperature Change when Different Volumes of Acid and Alkali are Mixed Prediction ========== My prediction is that the biggest temperature change will be when there are equal amounts of H+ ions and OH-, this is because create an optimum mixture for the ions to neutralise each other. Apparatus ========= v Empty plastic yoghurt cup v thermometer v Hydrochloric Acid v Sodium Hydroxide v Two measuring cylinders [IMAGE] Diagram =======
Limewater (alkali) - Irritant. * Phenolphthalein - May cause irritation of the respiratory and digestive tract if ingested. The reaction between the hydrochloric acid and limewater will also produce calcium chloride and water both of which have no hazards and are not dangerous at all. Phenolphthalein will not react with any of the other chemicals to produce anything dangerous. Also any reaction involving HCl can often be quite violent so great care must be taken however acids and alkalis tend
Analysis and Evaluation of Neutralisation An example of neutralisation is this: [IMAGE]Acid or Alkali + Base Salt + Water + Hydrogen This investigation will investigate the reaction of hydrochloric acid and sodium hydroxide where these two liquid compounds neutralise each other. We will be monitoring the temperature of the liquids as more of the hydrochloric acid (HCL) is added. [IMAGE]Sodium Hydroxide + Hydrochloric acid Sodium Chloride + water [IMAGE]NaOH + HCL NaCl + H2O I
Substances that neutralize acids are called alkalis. An acid is a substance that forms hydrogen ions (H+ ) when placed in water. It can also be described as a proton donor as it provides H+ ions. An example of an acid is hydrochloric acid (HCl), Sulphuric acid (H2SO4) etc. An alkali is a soluble base and forms hydroxyl ions (OH-) when placed in water. It can be called a proton acceptor and will accept hydrogen ions to form H2O. An example of an alkali is Sodium Hydroxide (NaOH). Neutralization
Method/Plan of the experiment: First of all, I will set up the apparatus as the diagram shows: Then, I will measure out the acid and alkali using the measuring cylinder. Once I have done that, I will pour the 25ml of Hydrochloric Acid in to the conical flask. I will also pour the 25ml of Sodium Hydroxide into the burette, and adding 1cm cubed of alkali at a time into the conical flask, I will record the temperature of the solution made by the two substances. By now, I will have also put
and an result of this is that the temperature will decrease because bonds are being made. Type of Acid - Different acids all have different properties and can cause different temperatures. Type of Alkali - This is the same as the type of acid but instead the different properties of an alkali. Type of Reaction - Different type of reactions will either be exothermic or endothermic. Example of this is a combustion reaction, which is exothermic because of the heat it gives out. These are
and Sodium hydroxide solution. Neutralization takes place when acids react with substances called bases. When they react their acidity is cancelled out, and the reaction always produces a salt and water. The base can be soluble (when called an alkali) or insoluble like copper (II) oxide. Neutralization can be used for: * Treating insect bites (that are acidic) * Making fertilizers and other salts in industry. * Reducing the acidity in soil, to make it better for plants to grow and
Sodium (Na) Sodium has an atomic number of 11 and a mass of about 23g. It is a silvery white-metallic element classified under the alkali metals. Sodium has been known since early times and was used by the people of Mesopotamia and Egypt to make glasses. Sodium is the sixth most common element found on the earth. It is usually not found in nature but more often in compounds such as salt (NaCl). Sodium conducts heat and electricity easily. Without this element life could not exist. Each compound
corresponding alkali metal salts. Some are even so insoluble that they resist weathering and leaching action in rainwater. Alkaline earth metals are extracted from the mineral ores like they have been for many decades. This second group of metals is also less reactive than the alkali metals. They do not need to have a specific storage procedure like that of the corresponding elements. These alkaline metals react with acids, and in certain temperatures of water. They are also harder than their alkali friends
Woman" and "Story of an Hour", both women were under the subjection of men. They were depicted as weak, loving the men of domination, but wanting to escape the men's shadows. In Silko's "Yellow Woman", the confusing western-type setting of dry, hot alkali-white crust dirt, rivers, and horses with the contrast of modern day mentioning of trucks, schools, and jello set the tone. The narrator's desire to seek solace in her grandpa who was dead(191). But the next best thing was to seek comfort in his story
is an acid-alkali titration (which is the determination of concentration by adding measured amounts of standard reagents to a known volume until the end point is reached). * Sulphuric acid is considered a strong acid, as it is completely in the form of ions in dilute solution. * Sodium carbonate is a weak alkali as it only partially forms ions in dilute solution. * For this titration methyl orange is the best indicator for the end point between a strong acid and weak alkali. [IMAGE]Na2CO3
Investigating the Effect of Concentration on the Temperature Rise, Heat Evolved and Heat of Neutralization for the Reaction Between HCl and NaOH Neutralization is the special name given for the reaction between an acid and an alkali leading to the formation of water molecules and a salt. The reactions between basic oxides, or hydroxides, and acids are very important and are called neutralizations. Since the metallic ions and anions from the acid do not change, the essential reaction of neutralization
use equal concentrations of acid and alkali at 0.1mols/dm³. This is a low concentration as the more concentrated the solution, the more rapidly the reaction takes place. This can be explained by the collision theory as increasing the concentration of the reactants increases the number of particles resulting in an increased number of collisions. If the reaction takes place too rapidly then it will be difficult to identify the exact point at which the alkali is neutralised and the results will
the second method I will do a titration experiment of lithium hydroxide(produced in experiment 1) The balanced equation of our reaction in experiment 2 is shown below; [IMAGE]LiOH + HCl LiCl + H20 Background Information Lithium is an alkali metal in group 1 of the periodic table. It is a metallic element and does not decompose however it is highly in contact with many other substances. It can react violently with water, the humidity in air, and the moisture in other substances releasing
00.20 Final Reading 26.45 26.45 26.05 27.00 25.85 25.90 26.10 Titration 26.45 25.95 26.05 27.00 25.85 25.90 25.90 pH slightly acidic neutral slightly acidic slightly acidic slightly alkali neutral neutral So the average of the closest three titration results are is: 25.95 + 25.90 + 25.90 / 3 = 25.92 The mass of Na2CO3 I used is 2.67g and the relative molecular mass of Na2CO3 is 106. So the number of mols of Na2CO3 I
etc). Elements within the same group similar chemical properties but often show a systematic variation in extent or speed of reaction as the group is descended. For example all of the group one elements (the alkali metals) react vigorously with water to form water soluble alkalis with the subsequent production of hydrogen gas. However, the speed of reaction increases down the group (lithium only reacts relatively slowly with water but francium and rubidium are explosive in the presence
from an area of low concentration to another area where it has a lower concentration until the overall concentrations are balanced. The Hydrochloric acid (HCl) diffuses into the gelatine cube of which contains Sodium Hydroxide (NaOH), which is an alkali. When the Hydrochloric acid combines with the Sodium Hydroxide they form salt and water, which is neutral therefore turning the pink cube to clear. Dependent variable: We are measuring the time taken for the pink indicator to turn clear when
When approaching the topic of hair chemistry, one may think about the question, where does hair come from? Saclike holes called follicles are located all over the human body. At the bottom of these follicles are a cluster of papilla responsible for the growth of hair. As the papilla, otherwise known as hair bulbs reproduce to make new hair cells, the old ones are pushed up towards the surface of the skin causing the hair to grow longer. This may seem like a simple concept to grasp. However, the process