Concept explainers
(a)
Interpretation:
The reason for using ethyl chloride (a spray that evaporates quickly) during a game to numb a sports injury should be explained.
Concept Introduction: Evaporation is the process of converting water (mostly) in liquid state to the gaseous state. Due to change in state of water from liquid to gas its temperature increases and energy is required for such change in state, Thus the water molecules undergoing evaporation, decreases the temperature of the surface by absorbing the heat energy from it.
(b)
Interpretation:
The reason for the faster evaporation of water in a flat dish than in the narrow vase should be determined.
Concept Introduction:
Evaporation is the process of converting water (mostly) in liquid state to the gaseous state. Due to change in state of water from liquid to gas its temperature increases and energy is required for such change in state, Thus the water molecules undergoing evaporation, decreases the temperature of the surface by absorbing the heat energy from it.
(c)
Interpretation:
The reason for the drying of sandwich that is placed on a plate as compared to the one placed in the plastic wrap should be determined.
Concept Introduction: Evaporation is the process of converting water (mostly) in liquid state to the gaseous state. Due to change in state of water from liquid to gas its temperature increases and energy is required for such change in state, Thus the water molecules undergoing evaporation, decreases the temperature of the surface by absorbing the heat energy from it. The process of evaporation increases on increasing the temperature.
Want to see the full answer?
Check out a sample textbook solutionChapter 10 Solutions
Basic Chemistry
- 1. (9 points) A 15.0 gram piece of metal is heated to 65.0°C and then dropped into 175 grams of 24.0°C water. The system eventually comes to a stable temperature of 35.5 C. (The specific heat of water is 4.184 J/g °C) a. Energy is absorbed by the water. What is qWATER? b. Energy is released by the metal. What is qMETAL? (this one is easy) c. What is the specific heat (Cs) of the metal?arrow_forward(10) Air is 21% by volume oxygen. Oxygen has a density of 1.31 g/L. What is the volume in liters of a room that holds enough air to contain 75 kg of oxygen?arrow_forward(7.6)Classify each of the following change or reaction as endothermic or exothermic. combustion of propane gas [Choose] [Choose endothermic vaporization of rubbing alcohol exothermic condensation of gas to liquid [Choose]arrow_forward
- A coffee cup calorimeter contains 25.0 g water at 23.8 C. A 5.00 g sample of an unknown metal at an initial temperature of 78.3 C was dropped into the calorimeter. The final temperature of mixture was 46.3 C. Calculate the specific heat of the metal. The specific heat of water is (4.184)arrow_forward9.38 The energy densities of various types of coal are listed below. Anthracite 35 kJ/g Bituminous 28 kJ/g Subbituminous 31 kJ/g Lignite 26 kJ/g Energy anUChe An unknown sample of one of these coals is burned in an apparatus with a calorimeter constant the kJ/C. When a 0.367-g sample is used, the temperature change is 8.75°C. Which type of coar s ae sample? dimen-arrow_forward11. A car has been fitted with an internal combustion engine that uses ethane as a fuel, which undergoes the following reaction when combusted: 2C2H6(g) + 702(g) → 4CO2(g) + 6H2O(g). Ethane (C2H6) has a molecular weight of 30.1 g/mol and a heat of reaction of -2,855.4 kJ/mol at 25°C. What is the AS° for this reaction at 25°C?arrow_forward
- 9:15 Question 14.d of 40 In welding, the temperature of the flame produced by the combustion of acetylene and oxygen varies based on the balance of the two gases in the reaction. The heat is used to melt metal so that pieces of metal can be joined together. 2 5 8 If the temperature of a neutral flame (equal proportions of oxygen and acetylene) is 3460 °F, what is this temperature in °C? °C 1 4 7 +/- Tap here or pull up for additional resources . LTE Submit 3 6 9 O XU x 100arrow_forwardThe combustion of wood produces an average of 15 000 kJ/kg. Suppose 4.30 kg of wood is burned in a fireplace that circulates heat around a house containing 800.0 kg of air (Cair = 1.02 kJ/kg°C), increasing the average air temperature of the house from 18°C to 23°C. a. What percentage of the wood's energy went directly into heating the air? (3) b. Brick (in addition to being non-flammable) has a high specific heat capacity. Why does it make sense in terms of energy efficiency to surround fireplaces with brick? (2)arrow_forwardDiborane is a highly reactive chemical that is used in rocket propellants. It reacts with chlorine to release 755 kJ of energy. What is the mass of diborane added to a bomb calorimeter if the specific heat capacity is 8.82 kJ/kg°C and the change in temperature is 30°C? (I:3)arrow_forward
- (6.37. Diatomic Elements The stable forms of hydrogen and oxygen at room temperature and pressure are gas phase, diatomic molecules H₂ and O₂. What is the sign of AH for the following processes? book Wiatomic es.a a. A solid with metallic properties is formed when hydrogen gas is compressed under extremely high pressures: £ show do 6.20 wirk?. ed in no H₂(g) → H₂(s) b. High-energy light shines on oxygen gas in the reaches of the atmosphere, converting oxygen gas to upper oxygen atoms: FAST 10 E,S O₂(g) → 2 0(g)arrow_forwardA. 7. Different conditions can affect the rates of chemical reactions. How is the rate of an endothermic reaction generally affected if the temperature is raised? Higher temperatures speed up chemical reactions. O Higher temperatures cause chemical reactions to fluctuate. O Higher temperatures stop chemical reactions. O Higher temperatures slow down chemical reactions. PREVIOUS 7 of 25 NEXTarrow_forwardHow many joules of energy are absorbed when 36.2 grams of water is evaporated? (delta)Hfus = 6.01 kJ/mol (delta)Hvap = 0.0845 kJ/molarrow_forward
- Chemistry: Principles and PracticeChemistryISBN:9780534420123Author:Daniel L. Reger, Scott R. Goode, David W. Ball, Edward MercerPublisher:Cengage LearningChemistry for Engineering StudentsChemistryISBN:9781337398909Author:Lawrence S. Brown, Tom HolmePublisher:Cengage LearningLiving By Chemistry: First Edition TextbookChemistryISBN:9781559539418Author:Angelica StacyPublisher:MAC HIGHER
- Chemistry: Principles and ReactionsChemistryISBN:9781305079373Author:William L. Masterton, Cecile N. HurleyPublisher:Cengage LearningChemistry by OpenStax (2015-05-04)ChemistryISBN:9781938168390Author:Klaus Theopold, Richard H Langley, Paul Flowers, William R. Robinson, Mark BlaserPublisher:OpenStax