217 - Chemistry Questions Answers

Boron is  a chemical element produced by cosmic ray spallation. Chemically uncombined Boron which is classified as a metalloid is not found naturally on earth. Several allotropes of Boron exist. Natural Boron is composed of two stable isotopes one of which is Boron 10, used as a neutron capturing agent.

     A + 3B


--------->


2C + D

     1    1/2                0     0

    1-x   1/2-3x          2x    x

according to the given condition 1/2 - 3x = 2x

                                        so 1/10 = x

so 3x = 3/10

so % = 0.3*100/0.5 = 60

0.75 mole water contains ...................................... 0.25 mole C₂H₅OH

so 0.75*18 gm contains ....................................... 0.25 mole

now calculate moles of alcohol in 1000 gm water. It will be molality

similarly

0.75 mole water contains ...................................... 0.25 mole C₂H₅OH

so 0.75*18 gm contains ....................................... 0.25*46 gm

so 0.75*18+0.25*46 gm solution contains ........................... 0.25 mole alcohol

so (0.75*18+0.25*46)*0.967 ml solution contains ............................. 0.25 mole alcohol

now calculate moles of alcohol in 1000 ml solution. It will be molarity

                      C₂H₄O -------------->           CO           +           CH₄

          t                                          P (C₂H₄O)

         0                                          116.6

         5                                          116.6-[122.56-116.6] = 116.6-5.96 = 110.64

         7                                           116.6-[125.72-116.6] = 116.6-9.12 = 107.48

   similarly others then find k for different readings by first order equation. k will be same for all readings.

Different oxidation no. are shown by f group elements and it is the property of element so there is no definite rule for getting these ox. no. A general oxidation no. for a family can be understand but if element is showing more oxidation no. then you should remember it by remembering compounds in these oxidation no. 

The classification is based on the number of pairs of electrons a ligand can donate.

matter is one of the fundamental constituent of the universe

because in ideal solution there is no interaction between the two liquids present in the solution

let x in HA and 1-x in HB

so according to the given condition -13.7x-12.7(1-x) = -13.5

solve

gas in gas is a solution but interaction between the molecules play almost no role so these solutions are addressed as mixtures