Topic: Acids and Bases.
Introduction
Acids are chemical agents that, when mixed with water, release hydrogen ions. Acids have a pH of under 7 on the pH scale.(Williams, 2016) An acid produces a sour taste, like Vinegar, and gives off a strong smell, that burns the human nose. Acids are often very sticky, and react strongly with metals, and create a chemical reaction to form H2. (Guch, 2003) A Base is the complete opposite of an Acid, and describes a substance that is above 7 on the pH scale. Bases have a more higher potential than Acids to accept Hydrogen Ions. This means that rather than releasing ions, as an Acid would, a Base accepts the ions.(Morrissey, 2016) Similar to Acids, Bases provide a Bitter taste, like Cocoa Beans, or Bicarb Soda. Bases, unlike Acids, do not usually give off a distinct smell, but are usually quite slippery. Bases react with most oils and fats, such as Detergent reacting with human skin, and slowly breaking down the oils and fats in the skin tissue.(Guch, 2003)
The universal indicator is used for specifying whether a substance is a Base, Neutral, or an Acid along the pH scale, by measuring the concentration of H3O+ ions in a substance. (N.a, 2016) The pH scale is a scale that determines whether a substance is an Acid product, or a Basic product. The ‘H’ in pH stands for Hydrogen, however, the ‘p’ is often debated, therefore is thought of as the power of the hydrogen. (Morrissey, 2016) The pH scales ranges from ranking between 0 (Being more
10. A pH scale describes the degree of acidity or alkalinity of a substance. 0 to 6.9 indicates an acidic solution, 7.1 to 14 indicates an alkaline solution, and 7 indicates a neutral solution.
An example would be pure water. Most of the time the pH is determined by pH paper but there are also other ways to determine the pH. For example, in this lab, cabbage juice was used. Cabbage juice is a great pH indicator because it can be homemade and easy to access.
PH sensors are used in many scientific laboratories to measure the hydrogen-ion concentration of a liquid substance and to determine the basicity and acidity of a liquid. PH meters measure the electrical potential difference between a reference electrode probe and a pH electrode probe. Since these probes are very sensitive, they are required to be kept cleansed from contaminants. If exposed to contamination, one risks faulty or unreliable data, since their accuracy is dependent on a regular calibration and upkeep. To avoid this risk, and accurately measure hydrogen-ion concentration, the probes are kept in a buffer solution and calibrated before each use. [1]
“The pH of a solution is a measure of the molar concentration of hydrogen ions in the solution and as such is a measure of the acidity or basicity (sic) of the solution. The letters pH stand for power of hydrogen and the numerical value defined as the negative base 10 logarithm of the molar concentration of hydrogen ions.” (PH, 2002). The pH scale is from 0 to 14. When the pH is higher, the hydrogen ions are fewer and the substance considered alkaline. This means when a pH unit increases by one, there is a tenfold change in the hydrogen ion. For example, if a substance has a 7 pH, it has 10 times as many as hydrogen ions available as 8 pH. A lake having a water pH between 6.5 and 8.5 is considered to be neutral. Researchers tested Peckham Park lake water monthly from August 2015 to April 2016 for water pH levels. A water quality PH test strip taken from a jar and dipped into the lake. After a few minutes, the strip will turn a color and this color determines the pH. The jar the strips came in has a chart of the colors on the back which compared to the color on the strip. The lake tested monthly using the PH test strips, which show the pH level, hardness, toxic, etc. using color-change
The purpose of this semester long experiment was to determine an unknown organic acid. An organic acid is an organic compound with acidic properties. A base reacts with acids to form salts. Titrations are used to determine the concentration of unknown substances. The purpose of the KHP experiment was to determine the molarity of NaOH. HCl titrations are mainly to check technique and used to verify the molarity of NaOH solution. The hypothesis is that this acid is C4H3OCOOH.
The problem that was trying to be solved in this study deals with analyzing unknown solutions. In this particular case, a chemical company has several unknown solutions and to correctly dispose of them they need to know their properties. To figure out the properties several qualitative tests were performed throughout the study (Cooper 2012).
Acids differ considerable as to their strength. The difference between weak and strong acids can be as much as 10 orders of magnitude. Strong acids dissociate more completely than weak acids, meaning they produce higher concentrations of the conjugate base anion (A-) and the hydronium cation (H30+) in solution.
pH is also known as a measure of hydrogen ions in a solution. A hydrogen ion is the nucleus of a hydrogen atom being split from its electron. Studying the pH of different types of soil being placed in a control group such as tap water will represent the acidity or alkalinity of the matter. The pH scale begins at 0 and goes all the way up to 14, pH 7 being its neutral point, which isn’t acidic or basic. A neutral point on the acidic scale is in the middle, anything lower than the neutral point (7), is acidic, and anything higher than the neutral point is considered basic or “alkaline”.
Bases are a substance with a pH higher than 7, and have a high concentration of hydroxyl ions. Bases can react with acids in order to neutralise them in order to form salt and water. Bases are normally metal oxides or metal hydroxides. Sodium hydroxide for example is a base.
When using different methods to measure pH levels there are some tools that can be useful. Some more than others but by putting into action the different methods it may determine which tools will work best and give the best results when testing the pH within a solution. The pH, which stands for the proportion of hydrogen ions in a solution, could be acidic (acidosis), neutral or basic (alkaline). The pH scale goes from numbers 1 through 14. A pH of 7 is neutral;
My science fair topic will be measuring the acidic levels in different companies of water bottles such as Aquafina, Dasani, Evian, Fiji, Miami Dade Tap Water, Penta, Publix Spring Water, Smart Water, Smart Water, Volvic, Voss, and Zephyrhills. Bottled water has been tested for its ppm (parts per million) to measure the amount of particles inside the water. The pH scale is a measurement of how acidic or basic an aqueous solution is. The pH scale has a range of 0-14; numbers less than 7 are considered acidic and numbers greater than 7 are considered basic. An acidic pH level means that the solution has more free hydrogen ions, and a basic pH level means that the solution has more free hydroxyl ions. pH is reported in logarithmic units and an increase or decrease of one on the pH scale has a 10-fold change. The negative logarithmic of the hydrogen ion concentration calculates the pH level of a solution. This is why pH stands for the potential of hydrogen and it calculate din
By using acid-base titration, we determined the suitability of phenolphthalein and methyl red as acid base indicators. We found that the equivalence point of the titration of hydrochloric acid with sodium hydroxide was not within the ph range of phenolphthalein's color range. The titration of acetic acid with sodium hydroxide resulted in an equivalence point out of the range of methyl red. And the titration of ammonia with hydrochloric acid had an equivalence point that was also out of the range of phenolphthalein.. The methyl red indicator and the phenolphthalein indicator were unsuitable because their pH ranges for their color changes did not cover the equivalence points of the trials in which they were used. However, the
What Is a Lewis Base? What makes a solution a base? Bases are solutions that are generally described as bitter and slippery or slimy feeling. However, how can we tell in an acid-base chemical reaction, which chemical compound is a base?
a measure of acidity and alkalinity of a solution that is a number on a scale on which a value of 7 represents neutrality and lower numbers indicate increasing acidity and higher numbers increasing alkalinity and on which each unit of change represents a tenfold change in acidity or alkalinity and that is the negative logarithm of the effective hydrogen-ion concentration or hydrogen-ion activity in gram equivalents per liter of the solution; also : the condition represented by a pH number
An acid-base titration is the determination of the concentration of an acid or base by exactly neutralizing the acid/base with an acid or base of known concentration. This allows for quantitative analysis of the concentration of an unknown acid