JEE Main & Advanced JEE Main Paper (Held On 10 April 2015)

  • question_answer
    A sample of a hydrate of barium chloride weighing 61 g was heated until all the water of hydration is removed. The dried sample weighed 52 g. The formula of the hydrated salt is : (atomic mass, Ba = 137 amu, Cl=35.5 amu) JEE Main Online Paper (Held On 10 April 2015)

    A) \[BaC{{l}_{2}}.3{{H}_{2}}O\]

    B) \[BaC{{l}_{2}}.2{{H}_{2}}O\]

    C) \[BaC{{l}_{2}}.{{H}_{2}}O\]

    D) \[BaC{{l}_{2}}.4{{H}_{2}}O\]

    Correct Answer: B

    Solution :

                     Weight of Hydrated \[BaC{{l}_{2}}=61g\] Weight of Anhydrous \[BaC{{l}_{2}}=52g\] Loss in mass \[=9g\] Assuming \[BaC{{l}_{2}}.x{{H}_{2}}O\] as hydrate Mass of \[{{H}_{2}}O=9g\] Moles of \[{{H}_{2}}O=\frac{9}{18}=0.5\] Grass molecular let of \[BaC{{l}_{2}}=208\]% of \[{{H}_{2}}O\] in this hydrated \[BaC{{l}_{2}}=\frac{9}{61}\times 100=14.75%\] \[=\frac{18x}{208+18x}\times 100\]on solving \[x=2\] This percentage is present in \[BaC{{l}_{2}}.2{{H}_{2}}O\]


You need to login to perform this action.
You will be redirected in 3 sec spinner