![ansver](/tpl/images/cats/User.png)
Answers: 2
![](/tpl/images/ask_question.png)
![](/tpl/images/ask_question_mob.png)
Another question on Chemistry
![question](/tpl/images/cats/himiya.png)
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) â 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.)
Answers: 1
![question](/tpl/images/cats/himiya.png)
Chemistry, 22.06.2019 12:00
What are the first two quantum numbers for the electrons located in subshell 4d? what are the first three quantum numbers for the electrons located in subshell 2s? how many electrons can be held in a sublevel l = 3? how many electrons can be held in the energy level n = 4? how many electrons in an atom can share the quantum numbers n = 4 and l = 3?
Answers: 1
![question](/tpl/images/cats/himiya.png)
Chemistry, 22.06.2019 19:00
Convert the temperature of dry ice, â77 âc, into degrees fahrenheit and kelvin.
Answers: 2
![question](/tpl/images/cats/himiya.png)
You know the right answer?
How does energy flow through an ecosystems...
Questions
![question](/tpl/images/cats/User.png)
![question](/tpl/images/cats/mat.png)
Mathematics, 20.07.2019 02:30
![question](/tpl/images/cats/mat.png)
![question](/tpl/images/cats/istoriya.png)
History, 20.07.2019 02:30
![question](/tpl/images/cats/obshestvoznanie.png)
Social Studies, 20.07.2019 02:30
![question](/tpl/images/cats/health.png)
![question](/tpl/images/cats/biologiya.png)
Biology, 20.07.2019 02:30
![question](/tpl/images/cats/mat.png)
Mathematics, 20.07.2019 02:30
![question](/tpl/images/cats/geografiya.png)
![question](/tpl/images/cats/istoriya.png)
History, 20.07.2019 02:30
![question](/tpl/images/cats/User.png)
![question](/tpl/images/cats/geografiya.png)
Geography, 20.07.2019 02:30
![question](/tpl/images/cats/mkx.png)
![question](/tpl/images/cats/User.png)
![question](/tpl/images/cats/en.png)
English, 20.07.2019 02:30
![question](/tpl/images/cats/ekonomika.png)
![question](/tpl/images/cats/geografiya.png)
![question](/tpl/images/cats/mat.png)
Mathematics, 20.07.2019 02:30
![question](/tpl/images/cats/biologiya.png)