Which statement is generally true about CaCl 2 ?

The masses of calcium chloride and water used were, 352.6 g and 487.0 g.

Explanation:

As we are given that 42.0 % calcium chloride by mass that means 42.0 grams of calcium chloride present in 100 grams of solution.

In the solution or mixture, 42.0 % calcium chloride and 58.0 % (100-42.0=58.0) water.

Now we have to determine the mass of calcium chloride for 839.6 grams of solution.

As, 100 grams of solution contains 42.0 grams of calcium chloride

So, 839.6 grams of solution contains  grams of calcium chloride

Thus, the mass of calcium chloride used is, 352.6 grams.

Now we have to determine the mass of water.

Mass of water = Mass of solution - Mass of calcium chloride

Mass of water = 839.6 g - 352.6 g

Mass of water = 487.0 g

Thus, the mass of water used is, 487.0 grams.

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"among the transition metal elements, manganese and zinc have a slight lowering of electronegativities. the reason behind this is that the nuclear charges of these elements are slightly weaker than the other transition metal elements due to the way their valence electrons are filled up. both manganese and zinc have their valence electrons filled up to the 4th shell with 1 pair of electrons (4s2) completely occupying it. although the electrons in the 3rd shell (3d) are yet to be paired since the outer most shell is filled up, the ability of the nucleus to attract electrons is lessened. hence,   the electronegativity (or the ability to attract electrons) is lessened."