PLease guys, please. I really need help
...
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) → 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
Chemistry, 22.06.2019 15:00
What is the most important factor in determining climates.
Answers: 1
Chemistry, 22.06.2019 20:40
Select the correct value for the indicated bond angle in each of the compounds. o−o−oo−o−o angle of o3 90° 109.5° < 109.5° 120° < 120° 180° f−b−ff−b−f angle of bf3 180° < 109.5° < 120° 120° 109.5° 90° f−o−ff−o−f angle of of2 < 120° 120° 90° 109.5° 180° < 109.5° cl−be−clcl−be−cl angle of becl2 90° 109.5° 180° 120° < 109.5° < 120° f−p−ff−p−f angle of pf3 90° 109.5° < 109.5° 180° 120° < 120° h−c−hh−c−h angle of ch4 90° < 109.5° 180° 120° < 120° 109.5°
Answers: 1
Chemistry, 23.06.2019 08:30
Kelly has come up with an explanation for why her sister is sometimes in a good mood and other times in a bad mood. she speculates that it is based on the hours of sleep her sister got the previous night. this explanation for her sister's behaviors is an example of a(n)
Answers: 3
History, 09.12.2021 19:30
Business, 09.12.2021 19:30
Mathematics, 09.12.2021 19:30
Mathematics, 09.12.2021 19:30
English, 09.12.2021 19:30
History, 09.12.2021 19:30
Mathematics, 09.12.2021 19:30
Mathematics, 09.12.2021 19:30
Mathematics, 09.12.2021 19:30
Physics, 09.12.2021 19:30
Mathematics, 09.12.2021 19:30