Chemistry: Molarity and Stoichiometry Directions: Using the definition of molarity, the given balanced equations, and stoichiometry, solve the following problems. Please submit your work via the link provided. 1. Calcium hydroxide (“slaked lime”) and sulfuric acid react to produce calcium sulfate and water according to the following balanced equation: Ca(OH)2(aq) + H2SO4(aq) ⋄ CaSO4(s) + 2 H2O(l) a. How many liters of 0.2 M calcium hydroxide do you need in order to have 6.0 moles of calcium hydroxide?
Stoichiometry Practice 1. Calculate the mass of silver bromide produced from 22.5 g of silver nitrate in the following reaction: 2AgNO3(aq) + MgBr2(aq) ( 2AgBr(s) + Mg(NO3)2(aq) ans: 24.9 g AgBr 2. What mass of acetylene, C2H2, will be produced from the reaction of 90. g of calcium carbide, CaC2, with water in the following reaction? CaC2(s) + 2H2O(l) ( C2H2(g) + Ca(OH)2(s) ans: 37 g C2H2 3. Chlorine gas can be produced in the laboratory by adding concentrated hydrochloric acid to manganese(IV) oxide in the following reaction: MnO2(s) + 4HCl(aq) ( MnCl2(aq) + 2H2O(l) + Cl2(g) a.
20. mol H2 reacts with 8.0 mol O2 to produce H2O. Determine the number of grams reactant in excess and number of grams H2O produced. Identify the limiting reactant. 8.1 g H2 , 2.9 x 102 g H2O 17. How many litres of O2 gas are required to produce 100. g Al2O3?
Create a data table similar to the one below named Data Table: Oxidation-Reduction Experiment. 2. Take a 24-well plate: a. In well A1: Place 10 drops of Sodium Sulfate, Na2SO4 b. In well A2: Place 10 drops of Magnesium Sulfate, MgSO4 c. In well A3: Place 10 drops of Zinc Nitrate, Zn(NO3)2 d. In well A4: Place 10 drops of Iron (III) Chloride, FeCl3 e. In well A5: Place 10 drops of Copper (II) Sulfate, CuSO4 3.
In equation 2, the hydrogen is measured by the loss of mass. This is done my placing the reaction on a table top mass balance. There are also 3 independent variables that can be changed in this experiment: a) the mass of magnesium, b) the surface area of the magnesium (the magnesium is in strips and is the same size for all experiments), or c) the volume of hydrochloric acid used. In the final equation (3), the reaction is measured by looking at the yellow precipitate formed by the sulfur. When the reaction is cloudy, the experiment is complete.
The balanced equations for this reaction shows that the molar ratio of magnesium reacted to hydrogen gas produced is 1:1. Therefore, by determining the mass of magnesium that reacts and the number of moles that this mass is equal to, you will also be able to determine the number of moles of hydrogen gas produced. The volume of hydrogen gas produced will be measured directly on the scale of a gas-measuring tube. The gas laws of Boyle and Charles will be used to correct this volume, measured under laboratory conditions, to the volume the sample of gas would occupy at STP. The collected data (number of moles and volumes at STP) will be used to calculate that molar volume of the hydrogen gas.
Investigating the Chemical Composition of Alka Selzter Problem: How much sodium bicarbonate is in a tablet of Alka Seltzer? Purpose: To discover the amount of sodium bicarbonate, in grams, in a one tablet of Alka Seltzer. Materials: one Alka Seltzer tablet 50 mL of vinegar post-it note Triple beam balance beaker Procedure: 1) Put the post-it on the triple beam balance and zero the balance. 2) Measure the masses of the alka-seltzer tablet, and the beaker + vinegar. Record them.
Single Replacement Reaction Laboratory Modified from Glencoe Chemistry - Matter and Change, Glencoe McGraw-Hill, 2002 Objectives Observe a single replacement reaction Measure the masses of iron and copper Determine the mole ratios and the limiting reactant Chemicals Iron filings (Fe) – 20 mesh Copper(II) sulfate pentahydrate, (CuSO4·5H2O) Distilled water Materials Stir rod 100-mL beaker 250-mL beaker 25-mL graduated cylinder Weigh paper Balance Hot plate Beaker tongs Wire mesh insulated pad screen Distilled water wash bottles |Lab Data - Reaction of Copper(II) Sulfate and Iron | | Mass of empty 100-mL beaker |(g) | | | Mass of 100-mL beaker
,, II I Quantitative Measurements of the Solute Since the solute is the species involved in chemical transformations, our goal will be the determination ot"the number of moles of solute in a particular solution. To be definitive, you want to carry out a reaction that involves zinc iodide. Instead of getting the zinc iodide in the solid state, you go in the .lab and there is a flask that contains zinc iodide diss91ved in water (in the solution state). What might the label on the flask say that will tell you how much iodide there is in the water? · There are numerous measures of the amount of solute in solvent.