Textbook Question
More sulfuric acid (density = 1.8302 g/cm3) is produced than any other chemical—approximately 3.6 * 1011 lb/yr world-wide. What is the volume of this amount in liters?
Ch.1 - Chemical Tools: Experimentation & Measurement
Chapter 1, Problem 81
Sodium (Na) metal undergoes a chemical reaction with chlorine (Cl) gas to yield sodium chloride, or common table salt. If 1.00 g of sodium reacts with 1.54 g of chlorine, 2.54 g of sodium chloride is formed and 17.9 kJ of heat is released, how much sodium and how much chlorine in grams would have to react to release 171 kcal of heat?
Verified step by step guidance1
Step 1: Convert the given heat release from kilojoules to kilocalories. Use the conversion factor 1 kcal = 4.184 kJ to convert 17.9 kJ to kcal.
Step 2: Determine the heat released per gram of sodium chloride formed. Use the converted heat value from Step 1 and the mass of sodium chloride (2.54 g) to find the heat released per gram.
Step 3: Calculate the total mass of sodium chloride that would release 171 kcal of heat. Use the heat per gram value from Step 2 to find the required mass of sodium chloride.
Step 4: Use stoichiometry to determine the mass of sodium and chlorine needed. Start by writing the balanced chemical equation: 2 Na + Cl_2 → 2 NaCl. Use the molar masses of Na, Cl_2, and NaCl to find the mass of each reactant needed to produce the calculated mass of NaCl from Step 3.
Step 5: Calculate the mass of sodium and chlorine required. Use the stoichiometric ratios from the balanced equation and the molar masses to find the mass of sodium and chlorine needed to produce the calculated mass of NaCl.
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Stoichiometry
Stoichiometry is the calculation of reactants and products in chemical reactions. It involves using balanced chemical equations to determine the proportions of substances consumed and produced. In this question, stoichiometry is essential to relate the mass of sodium and chlorine to the amount of sodium chloride formed and the heat released during the reaction.
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Thermochemistry
Thermochemistry is the study of the heat energy associated with chemical reactions. It focuses on the changes in enthalpy (heat content) during reactions, which can be exothermic (releasing heat) or endothermic (absorbing heat). Understanding the heat released in the reaction between sodium and chlorine helps in calculating how much reactants are needed to achieve a specific heat release, such as 171 kcal.
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Molar Mass
Molar mass is the mass of one mole of a substance, typically expressed in grams per mole (g/mol). It is crucial for converting between the mass of a substance and the number of moles, which is necessary for stoichiometric calculations. In this problem, knowing the molar masses of sodium and chlorine allows for the determination of how much of each reactant is needed to produce the desired amount of heat.
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Related Practice
Textbook Question
Which has more kinetic energy, a 1400 kg car moving at 115 km/h or a 12,000 kg truck moving at 38 km/h?
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Textbook Question
Assume that the kinetic energy of a 1400 kg car moving at 115 km/h (Problem 1.78) is converted entirely into heat. How many calories of heat are released, and what amount of water in liters could be heated from 20.0 °C to 50.0 °C by the car's energy? (One calorie raises the temperature of 1 mL of water by 1 °C)
Textbook Question
Which of the following statements uses exact numbers? (a) 1 ft = 12 in. (b) 1 cal = 4.184 J (c) The height of Mt. Everest is 29,035 ft. (d) The world record for the 1-mile run, set by Morocco's Hicham el Guerrouj in July 1999, is 3 minutes, 43.13 seconds