The coefficients in a balanced chemical equation provide the mole-to-mole stoichiometry among the reactants and products. The molar mass (in g/mol) can be used as the conversion factor between moles and the mass of a substance. Thus, the balanced equation and molar masses can be used in conjunction with one another to calculate the masses involved in a reaction.
When methane (CH4) burns, it reacts with oxygen gas to produce carbon dioxide and water. The unbalanced equation for this reaction is
This type of reaction is referred to as a complete combustion reaction.
What coefficients are needed to balance the equation for the complete combustion of methane? Enter the coefficients in the order CH4, O2, CO2, and H2O, respectively.
What mass of carbon dioxide is produced from the complete combustion of 7.20×10−3g of methane?
What mass of water is produced from the complete combustion of 7.20×10−3g of methane?
What mass of oxygen is needed for the complete combustion of 7.20×10−3g of methane?
The Haber-Bosch process is a very important industrial process. In the Haber-Bosch process, hydrogen gas reacts with nitrogen gas to produce ammonia according to the equation
The ammonia produced in the Haber-Bosch process has a wide range of uses, from fertilizer to pharmaceuticals. However, the production of ammonia is difficult, resulting in lower yields than those predicted from the chemical equation.
1.81g H2 is allowed to react with 10.3g N2, producing 1.22g NH3.
What is the theoretical yield for this reaction under the given conditions?
What is the percent yield for this reaction under the given conditions?
“I think we had about 1,500 glasses on Monday and they were gone within about two hours after we opened,” said Ashley Rich, patient services supervisor at Shasta Eye Medical Group in Redding, according to Redding.com, the web site for the local newspaper.
The Fleischmann Planetarium and Science Center in Reno, Nevada sold out earlier this week and ordered another 10,000 pair, according to a local web site.
Looking as the sun without proper protection can damage your eyes. Sunglasses are NOT proper protection.
If you know a welder, you could be in luck. A safe substitute for eclipse glasses is No. 14 welder’s glass, used in goggles. There are also several clever ways to view the eclipse safely indirectly, including easy-to-make pinhole cameras and simply standing under a tree to look for dappled light that will reveal an image of the eclipse on the ground. Read More
Chevron dispatched remote-controlled submarines, which found oil seeping through fissures on the sea floor directly above N560. The blowout preventer, a three-story-tall valve assembly, automatically cut off oil flow at the wellhead. This would not become another BP (BP) disaster, in which the blowout preventer notoriously failed. Still, George Buck, president of Chevron’s Brazil subsidiary, ordered the Frade well shut down. Chevron sent 18 vessels in rotation to contain the oil on the surface, and it readied pyramid-shaped steel caps to cover the seepage points. Workers completed the job in just four days. Buck saw the situation as under control. And technically, it was.
A petroleum engineer in his mid-forties, Buck has an MBA and has worked for Chevron for 23 years. He is 6-foot-5, slender, soft-spoken, and earnest to the point of social awkwardness. He arrived in Brazil in 2009, having worked from Alaska to Texas to Indonesia. He lives with his family in Rio’s fashionable Ipanema beach district. He is not a man about town. After three years in Brazil, he speaks little Portuguese, relying heavily on translators. Nevertheless, on the Frade spill, Buck thought he had made himself quite clear. “Chevron takes full responsibility for this incident,” he said at a press conference in Rio on Nov. 21. At a congressional hearing in Brasília two days later, he added, “Sincere apologies to the Brazilian people and the Brazilian government.” Read More
Oil dropped to a 2012 low after China’s industrial growth unexpectedly slowed in April and concern grew that Europe’s debt crisis will worsen, reducing fuel consumption.
Futures fell 1 percent after industrial output increased in China by the least since 2009. Prices also slumped as Spain said it will force lenders to raise provisions against real estate holdings and JPMorgan Chase & Co. (JPM) reported a $2 billion trading loss. Crude declined a second week after U.S. supplies rose to a 21-year high.
“There are a combination of factors pushing oil lower,” said Stephen Schork, president of the Schork Group in Villanova, Pennsylvania. “There’s a heck of a lot of oil out there, so supply isn’t a problem, and recent economic data along with the problems in Europe point to lower demand.”
Crude for June delivery fell 95 cents to $96.13 a barrel on the New York Mercantile Exchange, the lowest settlement since Dec. 19. Prices slipped 2.4 percent this week and are down 2.7 percent this year.
Oil in New York may extend losses after settling below the 200-day moving average for the first time since Dec. 19. The technical indicator stood at $96.27. Buy and sell orders tend to be clustered near chart-support levels. Read More
This image was created with data acquired by the Atmospheric Infrared Sounder instrument (AIRS) on NASA’s Aqua satellite during July 2009. Image Credit: NASA/JPL
For 10 years, it has silently swooped through space in its orbital perch 438 miles (705 kilometers) above Earth, its nearly 2,400 spectral “eyes” peering into Earth’s atmosphere, watching. But there’s nothing alien about NASA’s Atmospheric Infrared Sounder, or AIRS, instrument, a “monster” of weather and climate research that celebrates its 10th birthday in orbit May 4.
AIRS, built by BAE Systems, Boston, under the direction of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., is one of six instruments flying on NASA’s Aqua spacecraft as part of NASA’s Earth Observing System. AIRS, along with its partner microwave instrument, the Advanced Microwave Sounding Unit (AMSU-A), has faithfully measured our planet’s atmospheric temperature, water vapor, clouds and greenhouse gases with unprecedented accuracy and stability. Over the past decade, AIRS and AMSU-A have improved our understanding of Earth’s global water and energy cycles, climate change and trends and how Earth’s climate system is responding to increased greenhouse gases.
Studies have shown AIRS has improved global weather prediction more than any other single satellite instrument in the past 10 years. In 2006, a group led by John Le Marshall of the National Oceanic and Atmospheric Administration demonstrated that use of AIRS data in weather forecasting models significantly improved forecast “skill” — the name of the calculation meteorologists use to quantify how close a forecast is to actual observed weather conditions.
“AIRS has performed beyond expectation, exceeding its mission objectives,” said AIRS Project Manager Tom Pagano of JPL. “The knowledge we’ve gained through AIRS has advanced our understanding of weather and climate, and demonstrated an important measurement technology. While the team can be proud of what’s been accomplished, we continue to look forward to new discoveries as we explore the connection between extreme weather and climate change.” Read More