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. Its pH is greater than 7 and turns red litmus paper into blue. Acid- base neutralization is done by adding an acid to a base or a base to an acid until the substance has equal hydrogen and hydroxide ions. This is used to determine unknown concentration of a …show more content…
Procedure A. Preparation of NaOH solution The molarity of a solution is the ratio of the number of solutes dissolved in a liter of solution. To figure out the needed mass (in grams) of NaOH pellets to be dissolved in a 0.25 L of water, remember that a mole is equivalent to the quotient of mass over the molar mass of the substance. This was used to rearrange the base formula and to derive the mathematical equation of mass in terms of molarity. mass (g) = (Molarity)(Volume)(Molar mass) The pellets were dissolved thoroughly then was used in filling up the 100 mL volumetric flask. The solution was mixed well …show more content…
Standardization of NaOH solution The prepared solution in part A was used to determine the acidity of the two different brands of soft drinks. But before it, the NaOH solution was standardized first. A 0.15 g of potassium acid phthalate was dissolved in 0.05 L of water in an Erlenmeyer flask. Afterwards, 3 drops of phenolphthalein was added. A 50 mL buret was obtained and was washed with NaOH solution. After filling the buret with NaOH (titrant) and preparing the KHP (analyte) in the Erlenmeyer flask, the solutions were titrated. The volume used from the NaOH solution was recorded. C. Determination of the Acidity of Soft Drinks First, the soft drinks were heated. Upon cooling, it was shaken until no bubbles were formed. 20 mL of each brand of soft drinks was titrated with NaOH solution. 3 drops of phenolphthalein was used as an indicator if it has already completely reacted. The acidity can then be calculated referring on the known concentration and volume of base; and the known volume of acid. IV. Data and observations Mass of beaker (g) 174.01 Mass of beaker + NaOH pellets (g) 174.54 Mass of NaOH pellets 0.53 TRIAL 1 TRIAL 2 Mass of potassium acid phtalate (KHP) (g) 0.15 0.15 final buret reading (ml) 30.75
A hot plate was placed under the ring stand. 50 mL of 3.0 M NaOH in a 250 mL beaker and a stir bar was placed in the beaker. The beaker with NaOH was placed on the hot plate and 3.75 grams of NaAlO2*5H2O was placed in the beaker. The temperature probe was placed in the beaker with the solution, not touching the bottom of the beaker. The solution was heated and stirred till the solution dissolved.
Question3: Experiment 3 The unknown acid sample was 1 • Monoprotic Acid Trails Initial NaOH solution (mL) final NaOH solution (mL) The volume of NaOH to titrate the acid (mL) Amount of Unknown Acid sample 1 (g) The moles of the Unknown Acid (mol) Molar mass of the Unknown Acid (g/mol) A 3.38 28.31 24.93 0.150 0.0026 57.69 B 0.18 29.32 29.14 0.175 0.0029
Next, about 10 mL of both solutions, Red 40 and Blue 1, were added to a small beaker. The concentration of the stock solution were recorded, 52.1 ppm for Red 40 and 16.6 ppm for Blue 1. Then, using the volumetric pipette, 5 mL of each solution was transferred into a 10 mL volumetric flask, labelled either R1 or B1. Deionized water was added into the flask using a pipette until the solution level reached a line which indicated 10 mL. A cap for the flask was inserted and the flask was invented a few times to completely mix the solution. Then, the volumetric pipette was rinsed with fresh deionized water and
Introduction Alka-Seltzer has been on the market since 1931 and has helped to relieve indigestion and upset stomach. The tablets began to fizz and bubble when dropped into water. “The fizziness happens when baking soda (sodium bicarbonate) and citric acid react chemically in water. They yield sodium citrate, water and carbon dioxide gas, which causes bubbles.” Based on this information, we will measure the reaction time of AlKa- Seltzer dissolved in 200 ml of water at 3 different tempertures in the first portion of this experiment.
Weak acid like acetic acid, which do not dissociate with pH value, penerates the taste cells and can also evoke the electrical response. In this mechanism, H+ ion inhibits the potassium channels, which function in the hyperpolarization of the cells. This combination of intake of H+ ion which depolarize the cells and the inhibation of hyperpolarizing channel, together leads to polarization of membrane. The acidic stimuli activates the receptors, which cause decrease in pH and release of transmitters, this cause the excitation of afferent nerve fibers to cortex, which helps in the sour taste sensation.
In the round-bottom flask (100 mL), we placed p-aminobenzoic acid (1.2 g) and ethanol (12 mL). We swirled the mixture until the solid dissolved completely. We used Pasteur pipet to add concentrated sulfuric acid (1.0 mL) to the flask. We added boiling stone and assembled the reflux. Then, we did reflux for 75 minutes.
Weighed 1 gram of NaC2H3O2 and mixed it with ionized water. Boiled 12 mL of 1.0M Acetic Acid added into a beaker containing the sodium carbonate on a hot plate until all the liquid is evaporated
The soda water will be stored in 5 different temperatures : 5℃, 15℃, 25℃, 35℃, and 45. The desired temperatures will be achieved by using the water bath and refrigerator. I chose phenolphthalein as the indicator, because it is commonly used for titration and is a weak acid. Phenolphthalein is usually used when the solution is strong base and weak acid. When it is added into an acidic solution, the solution will be colourless; when it is added into an alkaline solution, the solution will turn pink.
A mole is a unit of measurement that follows the rule of ; 1.00 mole = molar mass = 6.02 x 10^23 atoms/ ions/ molecules / formula units = 22.4 L of any gas at standard temperature and pressure. That formula was used to determine the mass of the anhydrated substance. A anhydrate is a substance with water heated out of it. The purpose of this lab was to determine how many moles of water are
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.
5. 150 ml of the solution in beaker A was added to the separating funnel with 10ml of chloroform. The funnel was gently shaken and vented to release the pressure. This was done five times. 6.
Acid and base balance of body is normally strongly controlled, keeping the arterial blood pH between 7.38 and 7.42. Acid and base is also important in human homeostasis regarding the appropriate balance between acids and bases; this is also called pH. The body is very sensitive to its pH level, so strong mechanisms exist to maintain it. When pH is imbalanced the protein become denatured and digested, enzymes lose their ability to function, and can cause death. Metabolic Acidosis and Alkalosis: Metabolic Acidosis and Alkalosis are caused by an imbalance of acids or bases and their excretion by the kidneys. Metabolic acidosis produces when the amount of acid in the body is increased through absorption of a substance that can be broken down to an acid.
Commercial vinegar, Yamaha brand 0.1 mol/dm3, NaOH soloution Phenolpthalein indicator soloution (50.00 ± 0.5 cm3 ) cm3 burrete (250.00 ± 0.5 cm3) volumetric flask a (250 cm3± 0.5 cm3)
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.
That caused a new initial reading of NaOH on the burette (see Table1 & 2). The drops were caused because the burette was not tightened enough at the bottom to avoid it from being hard to release the basic solution for titrating the acid. The volume of the acid used for each titration was 25ml. The volume of the solution was then calculated by subtracting the initial volume from the final volume. We then calculated the average volume at each temperature.