Chemistry MCQs for NEET — Practice Questions with Answers

The redox reaction between potassium dichromate and Mohr’s salt is : $ 6Fe^{2+} + Cr_2 O^{2-} _7 + 14H ^ + \rightarrow 6Fe ^ {3+} 2Cr ^ {3+} + 7H_2 O $

$ Number of particles \alpha Number of moles $ $ No. of moles of carbon = 24 \12 = 2 $

$ During the reaction, Cr_2O_7 ^{ 2-} changes to Cr^{3+} $. Hence the change in oxidation number of Cr is 6. $ \therefore Equivalent weight = { Molar mass \over 6 } $

$ In 2L solution, there are 0.02 mol Br ^ - ions and 0.02 mole so ^{ 2-} _4 $ $ \therefore 1 L of mixture X contains 0.01 mol Br ^ – and 0.01 mol SO ^{2-} _{4} $ ions. $ Hence, Y= 0.01 mol Ag Br Z= 0.01 mol BaSO_4 $

$ Mass of an electron = 9.108 \times 10 ^ {31} Kg $ $ No. of electron s in 1 Kg = { 1 \over 9.108 \times 10 ^ {-31} } $ $ = { 1 \over 9.108 \times 10 ^ {-31 } \times 6.023 \times 10^ {23} mol ^ {-1} }$ $ = { 10 ^ 8 \over 9.108 \times 6.023 } mol $

The volume of a liquid is typically measured in liters (L) or cubic meters (m^3). 1 L = 1 x 10^-3 m^3. Therefore, 2 L = 2 x 10^-3 m^3.

The incorrect statement is 'The properties of a compound are same as its constituent elements.' A compound has different properties than its constituent elements due to the formation of new bonds and the rearrangement of atoms in a specific way.