Answer:
fe(iron) + cl^2 (clorine) = fecl^3(iron cloride)
Answer: the area of the telescope lens is \textit{0,08507 ft}
Explanation: Happy I could help!
Answer:
a) 
b) NR
c) NR
d) 
e) NR
Explanation:
a) Nickel is more reactive than copper so the first one will displace the other:

b) Due to the higher reactivity the magnesium has compared to the zinc, the first will remain in solution and the second will reamin solid. So, NR.
c) No reaction occurs, gold is resistant to acid in normal conditions due to its characteristic as noble metal.
d) Chromium is more reactive than cobalt so the last one will be displaced:

e) Nothing happens, the reduction potencial of the hydrogen gas bubbled ins't enough to reduce the silver.
Answer:
The products to ZnBr2 + F2 -> Znf + Br2
When we balance this equation we get the following:
2ZnBr2 + F2 -> 2Znf + 2Br2
Hope this helps !!!