Chemistry, 19.12.2021 15:50 Messick127
The Earth’s ozone layer is under attack in part by chlorine released when ultraviolet radiation breaks apart certain fluorocarbons. Consider three fluorocarbons known as CFC-11 (CCl3F), CFC-12 (CCl2F2), and HCFC-22 (CHF2CL). (a) Calculate the percentage by weight of chlorine in each of these fluorocarbons. (b) If each kilogram of CFC-11 could be replaced by 1 kg of HCFC-22, by what percentage would the mass of chlorine emissions be reduced
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Chemistry, 22.06.2019 12:00
Which of the following is an example of physical change not a chemical change? a) a log gives off heat and light as it burns. b) a tree stores energy from the sun in its fruit. c) a penny lost in the grass slowly changes color. d) a water pipe freezes and cracks on a cold night.
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Chemistry, 22.06.2019 13:30
Astudent is trying to create a table that compares hypotheses, theories, and laws. hypothesis theory law do scientific researchers formulate it? yes yes yes does it explain why things happen? yes yes no yes yes yes is it used to make predictions? no yes yes which of the following questions would most likely fill the blank in the table? is it an intelligent guess? is it newly formulated? is it based on observations? has it been proved?
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To find the enthalpy of a reaction in the lab, you measured the of the reactants and the change during the reaction.
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Chemistry, 22.06.2019 23:00
Which type of intermolecular attractions holds ammonia molecules together with other ammonia molecules?
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The Earth’s ozone layer is under attack in part by chlorine released when ultraviolet radiation brea...
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