Observing a Limiting Reactant

Good Essays
Observing a Limiting Reactant
An experiment was carried out to predict the limiting reactant in a chemical reaction between Magnesium and Hydrochloric acid, using the mole concept.
Limiting Reactant:
It is the reactant that will deplete or will be used up first during a chemical reaction. Limiting reactant also determine how long the reaction will last for.
Balanced Equation:
Mg + 2HCl = MgCl2 + H2
The balanced equation is needed to determine the mole ratio between the two reactants. From the equation we know that the equation mole ratio is 1:2. However, we need the actual mole ratio to find out the limiting reactant. The actual mole ratio is calculated below:
Moles of 5.0g of Mg = 5.0/24.305 = 0.21 moles
Moles of HCl in 10ml of 6.0M = 6/1 x 0.01L = 0.06 moles Actual Mole Ratio (AMR) = 0.21/0.06 = 3.5
Equation mole Ratio (EMR) = 1/2 = 0.5
If AMR > EMR then the 2nd reactant, i.e. HCl is the limiting reactant and Magnesium is in excess.
Hypothesis: Hydrochloric acid will be the limiting react at stages 5 and 6 and Magnesium will be the limiting reactant at stage 7.
Procedure:
We were given two magnesium ribbons and a beaker of 6M HCl to carry out our experiment. Firstly, we recorded the mass of one of the Mg ribbon and wrote down any observations in our table. Then, we put the piece of magnesium ribbon into a clean test tube and added 10 drops of 6M HCl. We wrote down our observations while the reaction took place. We waited for the reaction to stop and added another 10 drops and watched the reaction for any significant changes. Then we added one drop at a time until the Magnesium had fully reacted. The table below contains all our observations: Substance (s) | Observations | Mg | * Silver grey * Around 5 cm long * Striped | Mg + 10 drops HCl | * Bubbles were produced * Reaction lasted for 10-15 seconds * Solvent has a chalky colour * Mg strip is a bit paler | Mg + 20

You May Also Find These Documents Helpful

  • Good Essays

    Limiting Reactants

    • 683 Words
    • 4 Pages

    ____________________________and ___________________________ Date ____________________________ Objectives: (1) To determine the amount of NaHCO3 in Alka Seltzer tablets by observing the amount of CO2 produced from the acid-base reaction of HCO3- with acetic acid (in vinegar). (2) To study the concept of limiting reactant. Background: Alka Seltzer is an effervescent tablet that contains aspirin (acetylsalicylic acid), citric acid, and sodium bicarbonate (NaHCO3). As soon as the tablet dissolves…

    • 683 Words
    • 4 Pages
    Good Essays
  • Satisfactory Essays

    Limiting Reactant Lab

    • 397 Words
    • 2 Pages

    During this lab, we found the excess reactant and limiting reactant between Aluminum and Copper (ll) Chloride. Using stoichiometry, we were able to make predictions. Through the reaction 2Al + 2CuCl₂ → 3Cu + 2AlCl₃ we carried out this experiment and determined that the limiting reactant was CuCl₂ and that the aluminum was in excess. We also determined the percentage yield of copper. Purpose: The purpose of this experiment was to determine the limiting reactant and percentage yield of the reaction…

    • 397 Words
    • 2 Pages
    Satisfactory Essays
  • Good Essays

    Limiting Reactant Lab

    • 1092 Words
    • 5 Pages

    The Relationship between Reactants and Products Introduction In a chemical reaction, the amount of starting material for a chemical reaction limits the amount of product that can be formed.1 The principle of limiting reactants relates to this lab because the limiting reactant is the substance that is used up first in a chemical reaction. The amount of product was limited by that reagent. The excess reactants were considered to be the other reagents that were presented in excess of the quantity that…

    • 1092 Words
    • 5 Pages
    Good Essays
  • Powerful Essays

    Experiment #8: Limiting Reactant Abstract In chemical reactions, the significance of knowing the limiting reactant is high. In order to increase the percent yield of product, increasing the limiting reactant, possibly, is the most effective. In this experiment we were able to calculate limiting reactants from the reaction of CaCl2. 2H2O + K2C2O4.H2O(aq). As a group, we obtained our salt mixture of calcium chloride and potassium oxalate, and weighed the mixture. We were able to make an aqueous…

    • 1743 Words
    • 6 Pages
    Powerful Essays
  • Good Essays

    Limiting Reactants Lab

    • 639 Words
    • 3 Pages

    LMounika Alluri Chemistry HL Block D 19/9/12 LAB REPORT #1 LIMITING REAGENTS INVESTIGATION Aim: To determine the limiting reagent and percent yield of the reaction between potassium iodide with lead (II) nitrate solution. Apparatus required: Safety glasses, funnel stands, watch glass, oven, electronic balance, wash bottle with distilled water, test tubes, 10.0mL 0.50M lead (II) nitrate, 10.0mL 0.30M of potassium iodide solution, two 100.0 mL beakers, funnel, filter paper. Reaction…

    • 639 Words
    • 3 Pages
    Good Essays
  • Good Essays

    caused by different limiting reactants. A precipitate results in a solid formed by an ionic compound. Calcium nitrate and copper sulfate will be added to separate beakers with approximately half of the solutions from the Büchner funnel system of each trial to test for the formation of precipitates. The limiting reactant is the reactant that will run out first in the chemical reaction. It is important to recognize which chemical or compound is the limiting reactant because the reactant in short supply…

    • 792 Words
    • 4 Pages
    Good Essays
  • Satisfactory Essays

    In a chemical reaction the reactant that runs out first is called the limiting reactant. A personal example would be when I am making candles. I have melted 20 lbs. of wax that yield 24 16 oz. size candle jars. As I am gluing the wicks into the jars I realize that I only have 20 wicks and I need 24 for the amount of wax that I have melted. This means that the wicks are the limiting reactant in my candle making.…

    • 83 Words
    • 1 Page
    Satisfactory Essays
  • Good Essays

    and background In an experiment, limiting reactant affect the “amount of the product.” In the other way, the product this reaction produce dependent on the limiting reactant. For example, 1000kg O2 and 1 gram H2 to form water. In this case, the 1 gram of H2 will be the limiting reactant. Same thing in displacement reactant. If one of the reactants is (Mole) less than the other one, then that reactants becomes the limiting reactants. Once the limiting reactants will completely be ran out of, the…

    • 706 Words
    • 3 Pages
    Good Essays
  • Good Essays

    Determining the Limiting Reactant and Percent Yield in a Precipitate Reaction (SMG 6D) AP Chemistry One example of a double replacement (metathesis) reaction is the mixing of two solutions resulting in the formation of a precipitate. In solution chemistry, the term precipitate is used to describe a solid that forms when a positive ion (cation) and a negative ion (anion) are strongly attracted to one another. In this experiment, a precipitation reaction will be studied. Stoichiometry…

    • 1310 Words
    • 6 Pages
    Good Essays
  • Good Essays

    Determining the Limiting Reactant and Percent Yield in a Precipitation Reaction Objectives: Observe the reaction between solutions of sodium carbonate and calcium chloride. Determine which of the reactants is the limiting reactant and which is the excess reactant. Determine the theoretical mass of precipitate that should form. Compare the actual mass with the theoretical mass of precipitate and calculate the percent yield. Materials: Balance 0.70 M sodium carbonate solution, Na2CO3(aq)…

    • 800 Words
    • 4 Pages
    Good Essays