Question

Complete the following reaction:
$+H_{2}O\left(l\right)+C{O}_2\left(g\right)+N{H}_3\left(g\right)\to$$+{\mathrm{NH}}_4\mathrm{Cl}\left(\mathrm{aq}\right)$

• A. $NaCl$(aq)
• B. $N{a}_{2}C{O}_3$(aq)
• C. $NaHC{O}_3$(s)
• D. $N{a}_{2}C{O}_3$(s)

Answer 1

Answer: (A), (C)

$NaHC{O}_3$(s)

The above represents Solvay's process and is used to obtain soda ash
($N{a}_{2}C{O}_3$).
Step I:
Brine is prepared.
$NaCl\left(s\right)+H_{2}O\left(l\right)\to NaCl\left(aq\right)$

Step II:
(a) The brine solution when passed through a tower containing ammonia gas becomes ammoniated brine.
(b) This is further treated with carbon dioxide gas.
$NaCl\left(aq\right)+H_{2}O\left(l\right)+N{H}_3\left(g\right)+C{O}_2\left(g\right)\to N{H}_{4}Cl\left(aq\right)+NaHC{O}_3\left(s\right)$

Step III:
Sodium hydrogen carbonate ($NaHC{O}_3$) that precipitates out of the solution is subjected to calcination-
$2NaHC{O}_3\left(s\right)\to N{a}_{2}C{O}_3\left(s\right)+C{O}_2\left(g\right)+H_{2}O\left(g\right)$