Answers: 2
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) โ h2(g) + zncl(aq)the student collects the hydrogen produced over water at 25 ยฐc. 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.)
Answers: 1
Chemistry, 22.06.2019 15:30
Which of the following are correct values for the ideal gas laws constant r
Answers: 1
Chemistry, 22.06.2019 15:30
Draw the lewis dot structure for each of the following polyatomic ions
Answers: 1
How does earth surface change over time? What elements influence these changes ?...
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