A) 5
B) 4
C) 3
D) 2
E) 1
Correct Answer: A
Solution :
First the given unbalanced equation is balanced by using following steps Step I. The equation is splitted into two half equations as \[Zn\xrightarrow[{}]{{}}Z{{n}^{2+}};\] \[NO_{3}^{-}\xrightarrow{{}}NH_{4}^{+}\] Step II. Now water molecules are added to the side deficient in oxygen and \[{{H}^{+}}\] are added to the side deficient in hydrogen as \[Zn\xrightarrow{{}}Z{{n}^{2+}};NO_{3}^{-}+10{{H}^{+}}\xrightarrow{{}}NH_{4}^{+}+3{{H}_{2}}O\] Step III. The number of electrons are balanced and the two half equations are added. \[[Zn\xrightarrow{\,}\,Z{{n}^{2+}}\,+2{{e}^{-}}]\,\times 4;\] \[NO_{3}^{-}+10{{H}^{+}}+8{{e}^{-}}\xrightarrow{{}}NH_{4}^{+}+3{{H}_{2}}O\] \[4Zn\xrightarrow{{}}4Z{{n}^{2+}}+8{{e}^{-}}\] \[\therefore \]\[4Zn+NO_{3}^{-}+10{{H}^{+}}\xrightarrow{{}}4Z{{n}^{2+}}+NH_{4}^{+}\] \[+3{{H}_{2}}O\](Net equation) or \[4Zn+No_{3}^{-}+10HCl\xrightarrow{{}}4Z{{n}^{2+}}+NH_{4}^{+}\] \[+5C{{l}_{2}}+3{{H}_{2}}O\] \[\because \]1 mole of\[NO_{3}^{-}\](or \[NaN{{O}_{3}}\])is reduced by = 10 moles of\[HCl\] \[\therefore \]\[\frac{1}{2}\]mole of\[NO_{3}^{-}\]will be reduced by \[=10\times \frac{1}{2}moles\text{ }of\text{ }HCl\] = 5 moles of\[HCl\]
You need to login to perform this action.
You will be redirected in
3 sec
