Pour vinegar onto beach sand from the Caribbean and the result is ...

[bobbie]

Pour vinegar onto beach sand from the Caribbean and the result is a lot of froth and bubbles. Pour vinegar onto beach sand from California, however, and nothing happens. Why?
 
  A) Beaches in tropical climates generally have remnants of volcanic deposit not present in California sand. These deposits contain soil with organic residue. Vinegar's acetic acid reacts with organic matter.
  B) The pH of the warm sands of tropical waters is well into the basic range, unlike the beach sand in California. Therefore, the acidic vinegar reacts with Caribbean beach sand but not with sand from California.
  C) Beach sand from the Caribbean and many other tropical climates is made primarily of the calcium carbonate remains of coral and shelled creatures. Vinegar is an acid and the calcium carbonate is a base.
  D) Caribbean beach sand contains deposits from the mouth of the Mississippi river which carries with it a great deal of contamination from urban waste. These warm water contaminates react with the acid in vinegar.

Question 2

Which of the half-reactions below would be complementary and balance the following half-reaction?
 
  Zn+2  Zn
 
  A) Cu  Cu+2
  B) K+  K
  C) 2 Cu  2 Cu+2
  D) 2 K+  2 K
  E) Cl2  2 Cl-

[yifu223]

Answer to Question 1

Answer: C

Answer to Question 2

Answer: A

[bobbie]

TYSM

[Hdosisshsbshs]

Thanks for the timely response, appreciate it