question_answer 43)

Calcium carbonate reacts with aqueous \[HCl\] to give \[CaC{{l}_{2}}\] and \[C{{O}_{2}}\] according to the reaction, \[CaC{{O}_{3}}(s)+2HCl(aq)\to \] \[CaC{{l}_{2}}(aq)+C{{O}_{2}}(g)+{{H}_{2}}O(l)\] What mass of \[CaC{{O}_{3}}\] is required to react completely with 25 mL of 0.7 5 M HCl?

Answer:

Number of moles of HCl used \[=\frac{MV}{1000}=\frac{0.75\times 25}{1000}\] \[=0.01875\] Number of moles of \[CaC{{O}_{3}}\] to react with HCl \[=\frac{1}{2}\times \] Number of moles of HCl \[=\frac{1}{2}\times 0.01875\] \[=9.375\times {{10}^{-3}}\] Mass of \[CaC{{O}_{3}}\] = Number of moles x Molar mass \[=9.375\times {{10}^{-3}}\times 100\] \[=0.9375g\]