Stoichiometry Lab Quiz NAME, Summaries of Stoichiometry

Download Stoichiometry Lab Quiz NAME and more Summaries Stoichiometry in PDF only on Docsity! Stoichiometry Lab Quiz NAME ________________________ NAME ________________________ Lab table number/letter _______ Date ______________Per_________ Sugar and potassium chlorate react when heated to produce carbon dioxide, water, and potassium chloride. The formula for sugar is C12H22O11. 1. Balance the chemical equation: sugar + potassium chlorate -----> carbon + dioxide water + potassium chloride ___ C12H22O11 ( )+ ___ _______ ( ) ___ _____ ( ) ___ _____ ( ) ___ _____ ( ) 2. Calculate the molar mass of sugar to four sig. figs. Molar mass of sugar: _________ 3. Calculate the molar mass of potassium chlorate four sig. figs. Molar mass of potassium chlorate: _________ 4. You are to use 1.00 g of potassium chlorate. Calculate the amount of sugar needed to exactly react with this amount of potassium chlorate. Show your work below. Use the correct number of sig. figs. for the answer. Mass of sugar needed _____________ 5. Measure the given amount of potassium chlorate into your 250 mL beaker. Measure the calculated mass of sugar needed into your 100 mL beaker. Mix the two in the lager beaker. Stir thoroughly and push out any lumps using your stirring rod. Label the beaker using a wax pencil with your lab table number and letter. Bring the beaker to the front of the room. Your teacher will ignite each mixture. Those who have correct formulas, equations, and work with a reaction that does not leave a lot of carbon ash, ignites easily, and shows the correct mass of sugar to be used will earn an A. Stoichiometry Lab Quiz NAME ________________________ NAME ________________________ Lab table number/letter _______ Date ______________Per_________ Sugar and potassium chlorate react when heated to produce carbon dioxide, water, and potassium chloride. The formula for sugar is C12H22O11. 1. Balance the chemical equation: sugar + potassium chlorate -----> carbon + dioxide water + potassium chloride ___ C12H22O11 ( )+ ___ _______ ( ) ___ _____ ( ) ___ _____ ( ) ___ _____ ( ) 2. Calculate the molar mass of sugar to four sig. figs. Molar mass of sugar: _________ 3. Calculate the molar mass of potassium chlorate four sig. figs. Molar mass of potassium chlorate: _________ 4. You are to use 1.10 g of potassium chlorate. Calculate the amount of sugar needed to exactly react with this amount of potassium chlorate. Show your work below. Use the correct number of sig. figs. for the answer. Mass of sugar needed _____________ 5. Measure the given amount of potassium chlorate into your 250 mL beaker. Measure the calculated mass of sugar needed into your 100 mL beaker. Mix the two in the lager beaker. Stir thoroughly and push out any lumps using your stirring rod. Label the beaker using a wax pencil with your lab table number and letter. Bring the beaker to the front of the room. Your teacher will ignite each mixture. Those who have correct formulas, equations, and work with a reaction that does not leave a lot of carbon ash, ignites easily, and shows the correct mass of sugar to be used will earn an A. Stoichiometry Lab Quiz NAME ________________________ NAME ________________________ chloride. The formula for sugar is C12H22O11. 1. Balance the chemical equation: sugar + potassium chlorate -----> carbon + dioxide water + potassium chloride ___ C12H22O11 ( )+ ___ _______ ( ) ___ _____ ( ) ___ _____ ( ) ___ _____ ( ) 2. Calculate the molar mass of sugar to four sig. figs. Molar mass of sugar: _________ 3. Calculate the molar mass of potassium chlorate four sig. figs. Molar mass of potassium chlorate: _________ 4. You are to use 1.05 g of potassium chlorate. Calculate the amount of sugar needed to exactly react with this amount of potassium chlorate. Show your work below. Use the correct number of sig. figs. for the answer. Mass of sugar needed _____________ 5. Measure the given amount of potassium chlorate into your 250 mL beaker. Measure the calculated mass of sugar needed into your 100 mL beaker. Mix the two in the lager beaker. Stir thoroughly and push out any lumps using your stirring rod. Label the beaker using a wax pencil with your lab table number and letter. Bring the beaker to the front of the room. Your teacher will ignite each mixture. Those who have correct formulas, equations, and work with a reaction that does not leave a lot of carbon ash, ignites easily, and shows the correct mass of sugar to be used will earn an A. Stoichiometry Lab Quiz NAME ________________________ NAME ________________________ Lab table number/letter _______ Date ______________Per_________ Sugar and potassium chlorate react when heated to produce carbon dioxide, water, and potassium chloride. The formula for sugar is C12H22O11. 1. Balance the chemical equation: sugar + potassium chlorate -----> carbon + dioxide water + potassium chloride ___ C12H22O11 ( )+ ___ _______ ( ) ___ _____ ( ) ___ _____ ( ) ___ _____ ( ) 2. Calculate the molar mass of sugar to four sig. figs. Molar mass of sugar: _________ 3. Calculate the molar mass of potassium chlorate four sig. figs. Molar mass of potassium chlorate: _________ 4. You are to use 1.25 g of potassium chlorate. Calculate the amount of sugar needed to exactly react with this amount of potassium chlorate. Show your work below. Use the correct number of sig. figs. for the answer. Mass of sugar needed _____________ 5. Measure the given amount of potassium chlorate into your 250 mL beaker. Measure the calculated mass of sugar needed into your 100 mL beaker. Mix the two in the lager beaker. Stir thoroughly and push out any lumps using your stirring rod. Label the beaker using a wax pencil with your lab table number and letter. Bring the beaker to the front of the room. Your teacher will ignite each mixture. Those who have correct formulas, equations, and work with a reaction that does not leave a lot of carbon ash, ignites easily, and shows the correct mass of sugar to be used will earn an A. TEACHER’S NOTES Concepts: The student will correctly write a balanced chemical equation based on the English language description. The student will correctly complete a stoichiometry calculation. The student will demonstrate proper use of a balance to measure chemical quantities. Time required: About one 50-minute class period including time for students to complete their calculations, measures, and for the teacher to ignite 15 of the mixtures. Student Materials: 1 - 100 mL beaker Vial of sugar (C12H22O11) 1 - 250 mL beaker Vial of potassium chlorate (KClO3) Stirring rod Wax pencil Teacher Materials: Fireproof board Bunsen burner (with long hose) Background: This lab activity is intended to be used an a quiz near the end of a stoichiometry unit. Students must complete a stoichiometry problem to determine the ideal amount of sugar to combine with a given amount of potassium chlorate and produce a mixture that leaves a minimum of ash after ignition. Because it produces flames and sparks it can be a motivating and fun exercise. Six different masses of the salt are used so that neighboring lab groups do not have identical masses to work with, which inhibits sharing data. Teacher Procedure: It is essential that students put ALL the lab reaction materials onto the balance to be weighed at the beginning and at the end of this experiment. This means the condiment cup, plastic wrap cover, sample of solid sodium carbonate, the small beaker and the two pipets of HCl (bulb down). Students need to be reminded of this and possible show an example. One recommendation is to draw and label a picture on the board. Collect the 250 mL beakers from each lab group, note the order in which they are turned in. Empty the material in each beaker onto the fireproof board. Ideally the board is large enough for all the samples to fit on the board at one time with about 3 cm between each pile. Place the board into the fume hood and turn on the exhaust. Connect the Bunsen burner to the fume hood’s gas supply. Put on goggles and a lab coat or apron. Then light the Bunsen burner. Use the Bunsen burner to ignite each pile of chemicals, announcing which group’s chemicals are being ignited. Apply the flames directly to the pile. Ideally, each pile will leave only a small amount of melted white potassium chloride and carbon ash, those that grow carbon “worms” (like those that come with a pack of fireworks), have used a large excess of sugar. Safety Precautions: The students are working with solids, but wearing in goggles at all times in the lab is recommended, particularly as the potassium chlorate is an eye irritant. The teacher should take appropriate care with the Bunsen burner and when lighting the piles of chemicals. Each pile should produce purple f lames and a few sparks (depending on how close to the correct stoichiometry each group has come). Potassium chlorate Very hazardous in case of skin contact (irritant), of eye contact (irritant), of ingestion. Hazardous in case of inhalation. Slightly hazardous in case of skin contact (corrosive). Prolonged exposure may result in skin burns and ulcerations. Over-exposure by inhalation may cause respiratory irritation.