Discovering the Concentration of Sodium Hydroxide and Citric Acid
Introduction:
This laboratory experiment focuses on determining the quantity of a substance that is existing in a certain solution, by using titration in the experiment, (French et al. 2014). A hypothesis for this experiment is that the unknown concentration of a solution will be identified. The objectives are to identify the concentration of citric acid and the concentration of sodium hydroxide in solutions of unknown concentration. In order to discover the concentration of a solution, acid-base titration must be executed during the experiment, (French et al. 2014). The standard solution (known concentration) is reacted entirely during titration due to stoichiometry located in the equation, and because the chemical reaction is between a base and an acid, the products formed from the reaction will be salt and water, (French et al. 2014). The equivalence point occurring in an acid-base titration will have the same amount of moles in H+ as in OH-. The equations that are used for this acid-base titration are as follows:
HCl(aq)+NaOH(aq)→NaCl(aq)+H_2 O(l)
H_2 SO_4 (aq)+2NaOH(aq)→〖Na〗_2 SO_4 (aq)+2H_2 O(l)
To determine the concentration of acid in the solution, the number of NaOH moles supplemented to equivalence point must be discovered, (French et al. 2014).
Because sodium hydroxide takes in water and is hydroscopic, the discovery of the concentration is required that sodium hydroxide is titrated against a
The purpose of this lab was to determine the limiting reactant in a mixture of to soluble salts and the percent composition of each substance in a salt mixture.
One of the most important skills to have in the chemistry lab is the understanding of how chemicals will react. Knowing for example, how a chemical will react with a metal, is an excellent way of determining the amount of a particular metal in a deposit. This knowledge was used in this lab to determine the amount of copper in an unknown sample mixture. It is also known that the determination of the percent concentration of a certain solution, will directly effect the percent transmission and absorption of a solution, dependent upon its dilution. By first testing known concentrations of a solution, and plotting this information graphically, a line is formed
was to determine the percentage by mass of acetic acid in vinegar using acid/base titration. The
Chemistry 102 is the study of kinetics – equilibrium constant. When it comes to the study of acid-base, equilibrium constant plays an important role that tells how much of the H+ ion will be released into the solution. In this lab, the method of titrimetry was performed to determine the equivalent mass and dissociation constant of an unknown weak monoprotic acid. For a monoprotic acid, it is known that pH = pKa + log (Base/Acid). When a solution has the same amount of conjugate base and bronsted lowry acid, log (Base/Acid) = 0 and pH = pKa. By recording the pH value throughout the titration process and determining the pH at half- equivalence point, the value of Ka can be easily calculated. In this experiment, the standardized NaOH solution has a concentration of 0.09834 M. The satisfactory sample size of known B was 0.2117 g. The average equivalent mass of the unknown sample was found to be 85.01 g, pKa was found to be 4.69, which was also its pH at half-equivalence point and Ka was found to be 2.0439×〖10〗^(-5). The error was 1.255% for equivalent mass and 0.11% for Ka. In other word, the experiment was very precise and accurate; the identity of the unknown sample was determined to be trans-crotonic by the method of titrimetry.
Methods: First, a burette, ring stand, clamp, and an empty flask were obtained. The burette, with the valve closed, was attached to the ring stand with a clamp, and the empty flask was placed below the burette. Next, 50mL of the NaOH solution were poured into the burette, and a small bit was drained into the empty flask to ensure that the tip of the burette was also full of NaOH solution. The volume of the NaOH in the burette was recorded. Next, approximately 0.6 grams of KHP were massed poured into an empty 125mL flask. Two drops of an indicator solution were added to the KHP
The Oxidation of a Secondary Alcohol with Sodium Hypochlorite experiment was performed to show how to change an unknown alcohol into a ketone. The unknown that was found for this experiment was Compound A. Once the ketone was found from the unknown alcohol, an IR and the boiling point was taken to try and figure out what the product and starting alcohol actually is. The first thing that is added to the 1.50 g of unknown compound A is 15 mL of 8.25% of NaOCl, which is a bleach solution. This reacted with the alcohol so the solution could then be tested using the iodide-starch paper. The reaction came out positive when tested because a blue, black spot appeared on the strip.
1. Purpose: The purpose of the experiment is to determine the formula of an unknown hydrate by following simple steps that includes finding the moles of hydrate and anhydrate and then use the mole ratio to write the formula. 2. Introduction: A hydrate is a compound that contains water with a definite mass in the form of H2O. Hydrates are often in the form of a crystal that can be heated and the water can be 'burned off' by turning it into steam.
Its concentration was found through a quantitative and qualitative titration testing. Because HCl is acidic, a 1.07M NaOH solution was used to titrate an aqueous solution of HCl (the unknown solution). The PASCO program gave the final results shown in Figure 1. A typical titration curve can be described as starting at the initial pH of the solution, then some acid/base is added, until a sharp curve either up or down takes the pH past a neutral of 7, and towards the pH level of whatever the added acid’s/base’s pH is (Clark6). The stronger the acid or base being titrated, the faster the change occurs, which means a sharper slope of the titration graph. Also, it is important to note the equivalence point on this titration graph. At the equivalence point “the correct amount of standard solution must be added to fully react with the unknown concentration” (Xavier3). In Figure 1, this equivalence point is shown by where the sharpest slope occurs in the curve, which is seen at about a pH of 5.0
During a titration the pH of the solution will be monitored using a pH meter from that we get a titration curve. The titration curve is then used to determine the equivalent molecular weight and Ka value of the unknown weak acid, from that we are
One milliliter of 6.00-M phosphoric acid was placed into a 125-mL Erlenmeyer flask using a volumetric pipette. Using a slightly larger pipette, six milliliters of 3.00-M sodium hydroxide was transferred into a 50-mL beaker. Then a disposable pipette was used to slowly mix the sodium hydroxide into the phosphoric acid while the solution was swirled around. Then both the beaker and flask were rinsed with 2-mL of deionized water and set aside. A clean and dry evaporating dish was weighed with watch glass on a scale. Then the solution was poured into the dish and the watch glass was placed on top. The solution was then heated with a Bunsen burner to allow for the water to boil off to reveal a dry white solid. After the dish cooled to room temperature it was once again weighed and the new mass was recorded.
The purpose of the experiment was to compare antacids by the amounts acid they neutralize to find the most effective antacid. Finding the most effective antacid is important because it will help others by allowing them to choose the best product for their heartburn. Titration is the process of which the unknown solutions concentration reacts with a known solution concentration. During the experiment, titration was used to calculate the moles of HCl neutralized by the antacid in this case was gelusil, by knowing the moles of HCl initially added to the flask and moles of HCl neutralized by the NaOH.
Experiment to investigate the amount of sodium hydroxide needed to neutralize the solution of vinegar
First, three titration curves and three second derivative curves were created to determine the average pH at the half-equivalence point from the acetic acid titrations. Titration curves were used as visuals to portray buffer capacity. The graphs and a table, Table 1, that showcased the values collected were created and included below. The flat region, the middle part, of Figures 1, 2 and 3, showed the zone at which the addition of a base or acid did not cause changes in pH. Once surpassed, the pH increased rapidly when a small amount of base, NaOH, was added to the buffer solution. Using the figures below and
The purpose of this lab was to use process titration to find concentration of an aqueous solution of Hcl(aq) , using KOH(aq) as the titrant.
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