Answer:Total energy gained by 15.71 g is 3090.6471 joules
Explanation:
Given:
Q = heat gained by the 15.71 gram mass of gold


c = specific heat capacity of gold = 0.1291
m = mass of gold =15.71 g

Heat gained by gold = 
=3090.6471 joules
Answer:C The final product cannot be converted back to the original ingredients.
Explanation:
2,4-DNP is negative: aldehyde and ketone absent
Chromic acid is negative: alcohol absent.
KMnO4 test negative: alkene absent
The only positive result is for Fe(OH)2.
Nitro group-containing compounds react with ferrous hydroxide to give amine and ferric hydroxide red ppt. Hence given compound contains the nitro group (-NO2).
AN element is composed from atoms with the same number of protons,
A compound contain two or more different elements