Question

1. in the following equations, list the number of atoms of each of the following atoms on the reactant side (left).

a. $co(no_{3})_{2}+(nh_{4})_{2}s\to cos + 2nh_{4}no_{3}$
co: ____ n:__ o:__ h:__ s:____
b. $2hgo+k_{2}ni(cn)_{4}+2h_{2}o\to ni(oh)_{2}+2koh + 2hg(cn)_{2}$
hg:____ o:__ k:__ ni:__ c:__ n:__ h:____
c. $3zncl_{2}+2k_{4}fe(cn)_{6}\to k_{2}zn_{3}fe_{2}(cn)_{12}+6kcl$
zn:____cl:__k:__fe:__c:____
n:____h:__s:____

Explanation:

Step1: Analyze equation a

For \(Co(NO_3)_2\), there is 1 \(Co\) atom. In \(Co(NO_3)_2\), \(N\) atoms: \(2\) (from \(NO_3\) group, 1 per \(NO_3\) and 2 \(NO_3\) groups). \(O\) atoms: \(6\) (3 per \(NO_3\) group, 2 groups). In \((NH_4)_2S\), \(N\) atoms: \(2\) (1 per \(NH_4\), 2 \(NH_4\) groups). \(H\) atoms: \(8\) (4 per \(NH_4\), 2 groups). \(S\) atoms: \(1\). Total \(N\): \(2 + 2=4\).

Step2: Analyze equation b

In \(2HgO\), \(Hg\) atoms: \(2\). \(O\) atoms: \(2\) (from \(HgO\)) + \(2\) (from \(2H_2O\)) = \(4\). In \(K_2Ni(CN)_4\), \(K\) atoms: \(2\). \(Ni\) atoms: \(1\). \(C\) atoms: \(4\) (1 per \(CN\), 4 groups). \(N\) atoms: \(4\) (1 per \(CN\), 4 groups). In \(2H_2O\), \(H\) atoms: \(4\).

Step3: Analyze equation c

In \(3ZnCl_2\), \(Zn\) atoms: \(3\). \(Cl\) atoms: \(6\) (2 per \(ZnCl_2\), 3 groups). In \(2K_4Fe(CN)_6\), \(K\) atoms: \(8\) (4 per \(K_4Fe(CN)_6\), 2 groups). \(Fe\) atoms: \(2\) (1 per \(K_4Fe(CN)_6\), 2 groups). \(C\) atoms: \(12\) (6 per \(K_4Fe(CN)_6\), 2 groups). \(N\) atoms: \(12\) (6 per \(K_4Fe(CN)_6\), 2 groups). There is no \(H\) and \(S\) in reactants.

Answer:

a. Co: \(1\), N: \(4\), O: \(6\), H: \(8\), S: \(1\)
b. Hg: \(2\), O: \(4\), K: \(2\), Ni: \(1\), C: \(4\), N: \(4\), H: \(4\)
c. Zn: \(3\), Cl: \(6\), K: \(8\), Fe: \(2\), C: \(12\), N: \(12\), H: \(0\), S: \(0\)