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Chemistry, 22.06.2019 11:40
Modern pennies are composed of zinc coated with copper. a student determines the mass of a penny to be 2.482 g and then makes several scratches in the copper coaling (to expose the underlying zinc). the student puts the scratched penny in hydrochloric acid, where the following reaction occurs between the zinc and the hcl (the copper remains undissolved): zn(s) + 2 hcl(aq) → h2(g) + zncl(aq)the student collects the hydrogen produced over water at 25 °c. the collected gas occupies a volume of 0.899 l at a total pressure of 79 j mmhg. calculate the percent zinc (by mass) in the penny. (assume that all the zn in the penny dissolves.)
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Chemistry, 23.06.2019 00:00
Mercury turns to a vapor at 629.88 k. how much heat is lost when 75.0 g of mercury vapor at 650 k condenses to a liquid at 297 k?
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Chemistry, 23.06.2019 01:30
Which of the following statements is true about energy quantization at the atomic level? electrons in the outermost orbits are the most stable. electrons in all the orbits around the nucleus have the same amount of energy. electrons in the orbit closest to the nucleus have the least amount of energy. electrons absorb or release the same amount of energy independent of the energy levels.
Answers: 1
Chemistry, 23.06.2019 03:30
If you need to add 27.50ml of a solution, which piece of glassware would you use to deliver this volume and explain how you would determine if the 27.50 ml was measured?
Answers: 1
If 273.1 mL of SO2 is allowed to react with 155.2 mL of O2 (both measured at 317 K and 46.8 mmHg ),...
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