i ) Cu (s) + 4 HNO3 (aq) --> Cu(NO3)2 (aq) + 2 NO2 (g) + 2 H2) (l) ii ) Cu(NO3)2 (aq) + 2 NaOH (aq) --> Cu(OH)2 (s) + 2 NaNO3 (aq) iii ) Cu(OH)2 (s) --> Cu (s)+ H2O (l) (a.) Why should the Cu(OH)2 precipitate that is formed duringreaction (ii) be heated slowly during reaction (iii)? (b.) Why does reation (i) have to be carried out in the fumehood? (c.) Is reaction (iii) considered to be: a. combination b. single displacement c.decomposition d. acid-base e. precipitation i ) Cu (s) + 4 HNO3 (aq) --> Cu(NO3)2 (aq) + 2 NO2 (g) + 2 H2) (l) ii ) Cu(NO3)2 (aq) + 2 NaOH (aq) --> Cu(OH)2 (s) + 2 NaNO3 (aq) iii ) Cu(OH)2 (s) --> Cu (s)+ H2O (l) (a.) Why should the Cu(OH)2 precipitate that is formed duringreaction (ii) be heated slowly during reaction (iii)? (b.) Why does reation (i) have to be carried out in the fumehood? (c.) Is reaction (iii) considered to be: a. combination b. single displacement c.decomposition d. acid-base e. precipitation
Explanation / Answer
a. The precipitate is being heated during reaction III is adecomposition reaction, which requires heat to proceedforward. b. It produces toxic NO2 gas c. Decomposition because it is going from a single moleculeinto its different elements/compounds