The reagent PCC in dry methylene chloride is successful in the selective oxidation of primary alcohols to aldehydes because:

The answer is sucrose.

Elements that have complete valence shells are found in group 18, also known as the noble gases. these gases possess the stable octet, and are neon, radon, xenon, etc.

  balanced chemical equations follow the law of conservation of mass and charges. the masses and charges on either sides of the equation should be balanced.in conservation of mass, the number of atoms of each element on left side should be equal to the number of atoms of each element on the right side of the equation.1)k₂so₄ + 2ca(no₃)₂ --> 2kno₃ + 2caso₄number of ions        left side             right side  k⁺         2                         2so₄²⁻   1                         2ca²⁺     2                         2no₃⁻     4                         2in this equation the masses of so₄²⁻ and no₃ are not balanced. therefore this equation violates the law of conservation of mass2)ti + 2 cl₂ > ticl₄        left side       right side  ti           1               1cl           4               4this equation follows the law of conservation of mass3)2c₂h₂ + 5o₂ > 4co₂   + 2h₂o              left side     right side  c               4               4h               4               4o             10             10this equation follows the law of conservation of mass4)baso₄ + 2naoh --> ba(oh)₂   + na₂so₄          left side       right side  ba       1                   1so₄²⁻     1                   1na         2                   2  oh⁻       2                   2this equation follows the law of conservation of massanswer is 1st equation