MolSynapsequestion bank

MolSynapse / Question bank / Mole Concept / Mole, molar mass, Avogadro number and molar volume

JEE Advanced levelSingle correct optionDifficulty 3 of 3mc144

2.86 g of a crystalline hydrate $Na X_{2} CO X_{3} \cdot x H X_{2} O$ loses all its water of crystallisation on heating and leaves 1.06 g of anhydrous $Na X_{2} CO X_{3}$ ( $Na = 23$ , $C = 12$ , $O = 16$ , $H = 1$ ). The value of x is

A5
B7
C10
D12

Answer: C

Water lost = 2.86 - 1.06 = 1.80 g = 0.1 mol. Moles of

Na X_{2} CO X_{3}

= 1.06/106 = 0.01. x = 0.1/0.01 = 10.

Practice Mole Concept More on Mole, molar mass, Avogadro number and molar volume

Previous questionNext question

More questions on Mole, molar mass, Avogadro number and molar volume