Concept explainers
Of much concern to environmentalists is radon-222, which is a radioactive noble gas that can seep from the ground into basements of homes and buildings. Radon-222 is a product of the decay of radiurn-226 that occurs naturally in rocks and soil in much of the United States. Radon-222, which has a half-life of 3.8 days, decays by emitting an alpha particle. Radon-222, which is a gas, can be inhaled into the lungs where it is strongly associated with lung cancer. Radon levels in a home can be measured with a home radon-detection kit. Environmental agencies have set the maximum level of radon-222 in a home at 4 picocuries per liter (pCi/L) of air. (5.2, 5.3, 5.4)
a. Write the balanced
b. Write the balanced nuclear equation for the decay of Rn-222.
C. If a room contains 24 000 atoms of radon-222, how many atoms of radon- 222 remain after 15.2 days?
d. Suppose a room has a volume of 72 000 L (
Want to see the full answer?
Check out a sample textbook solutionChapter 6 Solutions
Study Guide and Selected Solutions Manual for Chemistry: An Introduction to General, Organic, and Biological Chemistry
- Sulfur (2.56 g) was burned in a constant-volume calorimeter with excess O2(g). The temperature increased from 21.25 C to 26.72 C. The bomb has a heat capacity of 923 J/K, and the calorimeter contained 815 g of water. Calculate U per mole of SO2 formed for the reaction S8(s) + 8 O2(g) 8 SO2(g)arrow_forwardMarie Curie was born in Poland but studied and carried out her research in Paris. In 1903, she shared the Nobel Prize in Physics with H. Becquerel and her husband Pierre for their discovery of radioactivity. (In 1911 she received the Nobel Prize in Chemistry for the discovery of two new chemical elements, radium and polonium, the latter named for her homeland, Poland.) They and others observed that a radioactive substance could emit three types of radiation: alpha (), beta (), and gamma (). If the radiation from a radioactive source is passed between electrically charged plates, some particles are attached to the positive plate, some to the negative plate, and others feel no attraction. Which particles are positively charged, which are negatively charged, and which have no charge? Of the two charged particles, which has the most mass? Radioactivity. Alpha (), beta I(), and gamma () rays from a radioactive element are separated by passing them between electrically charged plates.arrow_forward89 A number of compounds containing the heavier noble gases, and especially xenon, have been prepared. One of these is xenon hexafluoride (XeF6), which can be prepared by heating a mixture of xenon and fluoride gases. XeF6 is a white crystalline solid at room temperature and melts at about 325 K. A mixture of 0.0600 g of Xe and 0.0304 g of F2 is sealed into a 100.0-mL bulb. (The bulb is heated, and the reaction goes to completion. Then the sealed bulb is cooled back to 20.0°C. What will be the final pressure in the bulb, expressed in torr?arrow_forward
- 4.61 What is actually measured by the octane ratings of different grades of gasoline?arrow_forwardThere are many greenhouse gases in our atmosphere besides CO2 which contribute to the greenhouse effect that keeps our Earth warm. In addition, many of these gases undergo reactions in the atmosphere, especially when photolyzed by sunlight. One such example is the collection of gases nicknamed “NOx”, which refers to nitrogen oxide (NO) and nitrogen dioxide (NO2). NOx is notorious for the production of ozone (O3) in the troposphere (where ozone contributes to air pollution) and the loss of ozone in the stratosphere (such as the ozone hole in Antarctica that allows harmful UV rays to penetrate to the surface). Imagine you are an environmental chemist trying to better understand the loss of ozone due to the presence of NOx – even in small quantities – in the stratosphere. You set up an experiment in which you have two flasks separated by a valve. Each flask has a pressure of 10 millibar (or 7.50 mmHg) and a temperature of -35.0°C, mimicking the conditions in the middle of the…arrow_forwardCalculate the energy when 125 g of lead react with oxygen gas to form solid PbO.arrow_forward
- hello, i need help with part a, b, and c. In the chemistry lab, one often has to work with very reactive metals such as sodium and lithium. Unfortunately, these same metals can react vigorously with water or oxygen and cause fires. Given the following information: (kJ/mol) (kJ/mol) Li2O(s) -597.9 Li+(aq) -278.5 Na2O(s) -416 Na+(aq) -240 K2O(s) -361 K+(aq) -251 CO(g) -110.5 CO2(g) -393.5 H2O(l) -286 OH-(aq) -230 CCl4(l) -135 SiO2(s) -911 LiCl(s) -409 NaCl(s) -411 KCl(s) -436 Cl-(aq) -167 Calculate ΔH° for the following reactions: 1a) 4 Li(s) + O2(g) --> 2 Li2O(s) 1b) 2Li(s) + CO2(g) ----> Li2O(s) + CO(g) 1c) 2Li(s) + 2H2O(l) ---> 2LiOH(aq) + H2(g)arrow_forwardCocaine (C17H21O4N) is a natural substance found in the leaves of the coca plant, which has been used for centuries as a local anesthetic and stimulant. Illegal cocaine arrives in the USA either as a pure compound or as the hydrochloride salt (C17H21O4NHCl). At 25oC, the salt is very soluble in water (2.50 kg/L), but pure cocaine is much less so (1.70 g/L). What is the maximum amount of salt (in gram) that can dissolve in 50.0 mL of water? [1 mark.] When a 25 mL aqueous solution that contains 62.50 g of the salt is treated with NaOH, the salt is converted to pure cocaine. How much water (in liters) is needed additionally to dissolve the formed pure cocaine? Round your final answer off to two decimal points. C17H21O4NHCl(aq) + NaOH(aq) → C17H21O4N(aq) + H2O(l) + NaCl(aq)arrow_forwardGiven these reactions, where X represents a generic metal or metalloid 1) H2(g)+12O2(g)⟶H2O(g)Δ?1=−241.8 kJ 2) X(s)+2Cl2(g)⟶XCl4(s)Δ?2=+344.1 kJ 3) 12H2(g)+12Cl2(g)⟶HCl(g)Δ?3=−92.3 kJ 4) X(s)+O2(g)⟶XO2(s)Δ?4=−935.3 kJ 5) H2O(g)⟶H2O(l)Δ?5=−44.0 kJ what is the enthalpy, Δ?, for this reaction? XCl4(s)+2H2O(l)⟶XO2(s)+4HCl(g)arrow_forward
- Cocaine(C17H21O4N) is a natural substance found in the leaves of the coca plant, which has been used for centuries as a local anesthetic and stimulant. Illegal cocaine arrives in the USA either as a pure compound or as the hydrochloride salt(C7H21O4NHCl). At 25 degrees celsius, the salt is very soluble in water(2.59kg/L), but pure cocaine is much less so(1.70g/L) a. What is the maximum amount of salt in grams that can dissolve in 50.0mL of water? b. When a 25mL aqueous solution that contains 62.50 g of the salt is treated with NaOH, the salt is converted to pure cocaine. How much water in liters is needed additionally to dissolve the formed pure cocaine,arrow_forward4 NH3 (g) + 5 O2 (g) 4 NO (g) + 6 H2O (g) ∆H = -905 J What is the value of ∆H if the reaction is multiplied by 3?arrow_forwardWHAT WILL YOU DO? In the final round of The Battle of Geniuses, you and your competitors were asked to guess the number of grains of rice in a 100 kg sack of rice. The contestant whose guess is closest to the actual number will win the prestigious prize, trophy, and a lifetime supply of rice :). How could you prepare for such a contest without actually counting the grains in a 100kg sack of rice? Ps. This question can be answered in relation of your knowledge about mole (of an atom). So, apply your knowledge about mole to answer this question.arrow_forward
- Chemistry for Engineering StudentsChemistryISBN:9781337398909Author:Lawrence S. Brown, Tom HolmePublisher:Cengage LearningChemistry & Chemical ReactivityChemistryISBN:9781337399074Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage LearningChemistry & Chemical ReactivityChemistryISBN:9781133949640Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage Learning
- Introductory Chemistry: A FoundationChemistryISBN:9781337399425Author:Steven S. Zumdahl, Donald J. DeCostePublisher:Cengage LearningChemistry: The Molecular ScienceChemistryISBN:9781285199047Author:John W. Moore, Conrad L. StanitskiPublisher:Cengage LearningWorld of ChemistryChemistryISBN:9780618562763Author:Steven S. ZumdahlPublisher:Houghton Mifflin College Div