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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) β h2(g) + zncl(aq)the student collects the hydrogen produced over water at 25 Β°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, 22.06.2019 17:30
In a heat of an engine, if 700 j enters the system, and the piston does 400 j of work what is the final internal (thermal) energy of the system if the initial energy is 1,500 j
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Chemistry, 23.06.2019 06:00
Which change will decrease the number of effective collisions during a chemical reaction? a. adding a catalyst b. increasing the surface area c. decreasing the temperature d. increasing the reactant concentrations e. increasing the volume of the reactants
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Chemistry, 23.06.2019 16:00
The table below shows a comparison of the different gas laws. some cells have been left blank. name variables constants equation boyle's law pressure, volume ? pv = k charlesβs law volume, temperature ? v = kt ? temperature, pressure volume, moles of gas p = kt ? pressure, temperature, volume ? which are assumed to be constant while using the combined gas law? 1. pressure 2. number of moles 3. volume and moles of gas 4. pressure and temperature
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Mathematics, 05.05.2020 07:04
History, 05.05.2020 07:04
Mathematics, 05.05.2020 07:04
Mathematics, 05.05.2020 07:04
Mathematics, 05.05.2020 07:04