Conclusion: Every compound has a uniquely identifying molar mass as well as individual properties. In this lab, the purpose was to use the properties that three unknown alkali metal carbonate powers have, to identify the molar mass. For the three unknown substances, they all were white powders of about the same texture, and they all reacted when added to hydrochloric acid. Based on these properties, it is impossible to distinguish which one is which due to the similarities, so it is necessary to solve for the molar mass since that is unique to every element and compound. In this lab, 30 mL of hydrochloric acid are reacted with the limiting reactant that is the unknown powder, either A, B, or C.The amount of acid is negligible due to it not …show more content…
After the reaction finishes, the amount of CO2 that was released is calculated and then using the molemap, it is possible to solve for the amount of the unknown substance. The grams of the unknown powder are then divided by the moles of the substance to get the molar mass. This molar mass is then compared to the molar mass of the known substances. Unknown substance A is lithium carbonate since the molar mass produced in the experiment is 66.68 g/mol and the molar mass of lithium carbonate is 73.89 g/mol. Unknown substance B has a molar mass of 146.70 g/mol which is inconclusive since it is too different from the other molar masses. Unknown substance C is sodium carbonate since the molar mass found in the experiment is 110.03 g/mol which is close to the actual molar mass of sodium carbonate that is 105.99 g/mol. Substance A is lithium carbonate since the lab produced 0.33g of CO2 which can be used to calculate the moles of the unknown substance. Since the moles of the unknown are 0.007498 mol, we can divide the original mass used in the experiment (0.50g) by this to get 66.68 g/mol as the molar mass. This then is relatively close to the molar mass of lithium carbonate which is 73.89
The purpose of the lab is to acquire the percent composition of zinc and copper. The procedure included obtaining a post 1983 penny and washing it with soap and water. Using a triangular file, we made an X on the penny. Then, we cleaned the top and bottom of the penny with steel wool until it was shiny. We rinsed the penny in acetone and dried it with paper towel.
The Controlled Variable for this experiment was mass and volume. When identifying an unidentified object finding the density is the easiest way to do it because, any pure substance has a specific density at a specific temperature and each element and compound has a unique density associated
each paper remained it's original color, thus concluding that the unknown was neutral. These results also led the students to believe the unknown was CaCl2 since it was listed in the neutral column. After the litmus test was conducted the students added a few drops of Na3PO4 to the unknown. When these two were combined a precipitate was formed. This final test on unknown F verified that it was CaCl2.
A two-hundred and fifty milliliter(ml) flask was zeroed out on the scale. Fifty milliliters of HCl was put into the flask and weighed. The unknown mixture was poured into the HCl while
Identification of an Unknown Compound using Quantitative and Qualitative Analysis Lauren Tremaglio Chemistry 1011 Lab, Section 16 Instructor: Steven Belina October 3, 2014 Our signatures indicate that this document represents the work completed by our group this semester. Experimental Design and Discussion of Results The objective of this experiment was to identify an unknown compound through quantitative and qualitative analysis. In order to find the identity of the unknown compound, an initial qualitative test for solubility was performed.
Use the evidence provided by the tests to identify the mystery powder. The mystery powder (#5) is the baking powder. My partners and I figured this out because the physical and chemical properties of both of the substances are very similar. For example, both powders are not soluble in water, and they both turned red when they reacted with the universal indicator.
The topic that the scientist has researched is the reaction rate of different particle sizes. In the experiment, the scientist will discover how the particle size of Alka Seltzer affects the rate of chemical reaction with water. The independent variable in the experiment is the particle size of the Alka Seltzer, while the dependent variable is the rate of reaction, or the volume of Carbon dioxide. The volume of carbon dioxide will be measured in ml. Also, a few of the constants in the experiment will be the amount of water, and amount of tablets.
Purpose: The purpose of this lab is to titrate an unknown solid acid (KH2PO4) with a standardized sodium hydroxide solution. After recording and plotting the data, the acid’s equivalence point will be recorded once the color changes. Using the equivalence point, the halfway point will be calculated, which is used to determine the acid’s equilibrium constant. The acid’s calculated equilibrium constant will be compared with the acid’s established pKa value.
I. Purpose: To experimentally determine the mass and the mole content of a measured sample. II. Materials: The materials used in this experiment a 50-mL beaker, 12 samples, a balance and paper towels. III.
Molar mass is the mass in grams in one mole of substance. The units for molar mass are in grams per mole. Molar mass is the same number as the formula mass that needs to be found except it is converted. Formula mass is the mass in atomic mass unit of one particle of
The mass we measured after the whole process came up, was 121.80g. The chemical reaction happened between the water and the tablet conserves the mass of the water. As a whole point, we claimed that there was a chemical reaction between the water and the tablet that produced carbon dioxide and the mass remained as same as before and after the
Introduction : The percent composition of a compound can be found by determining the mass of each element within that compound, and with this information, the empirical formula can be determined. The lab consisted of obtaining a magnesium ribbon and having it undergo chemical reactions to create solid magnesium oxide with the aim being identifying the percent composition and empirical formula of the compound. Background Information : To determine magnesium oxide’s percent composition and empirical formula, the masses of magnesium and oxygen separately must be found and then divided by the total mass and multiplied by 100 to find the percent makeup of each element within the compound. However, to obtain magnesium oxide, it had been synthesized from magnesium and various chemical reactions with only the initial mass of magnesium and the final compound’s mass being known.
The equation must be balanced in order to get the correct amount of the elements in the reaction to find out what is limiting or excess. The stoichiometry quiz 1 we took in class shows that you have to first balance the equation, find the limiting and excess reactants, then find the percent yield. When balancing an equation one has to follow the law of conservation of mass. So however much the equation starts out with is how much the equation needs to end with. “The law of conservation of matter states that matter can be neither created nor destroyed.”
AIM To design an investigation to study the kinetics of a reaction of your choice RESEARCH QUESTION With respect to hydrochloric acid (HCl), what is the order of reaction in the reaction between HCl and calcium carbonate (CaCO3) determined by changing the concentration of HCl and measuring the volume of carbon dioxide gas (CO2) collected in 30 seconds whilst keeping the mass of the powdered CaCO3 constant and the temperature of the reaction system at 25oC? BACKGROUND INFORMATION Calcium carbonate (CaCO3) is a chemical compound that is commonly found in rocks such as chalk, limestone, marble and travertine in all parts of the world. It also used as a form of medicine as a dietary supplement for a person with insufficient calcium intake because calcium is needed by the body for healthy bones, muscles, nervous system, and heart. CaCO3 is also used as an antacid to relieve
Introduction Strong acids and strong acids both dissociate completely in water forming ions. However, strong acids donate a proton to form H3O+ along with a conjugate base and strong bases accept a proton to form OH- along with a conjugate acid. The chemical behavior of acids and bases are opposite. When they are together, their ions cancel out and form a neutral solution. In this experiment, HCl and NaOH will react to form NaOH and H2O with these two steps: The overall reaction is: Both Na+ and Cl- ions combine to form NaCl.