Kcl and kbr are both ionic solids. a mixture of kcl and kbr has a mass of 3.595 g. when this mixture is heated in the presence of excess cl2, all of the kbr is converted to kcl. if the total mass of kcl present after this reaction is 3.129 g, what percentage (by mass) of the original mixture was kbr? (hint: be sure that you understand why the mass of the sample has decreased. it may if you write an equation for the reaction that converted the kbr to kcl.)

The percentage (by mass) of KBr in the original mixture was 33.1%.

Explanation:

The mixture of KCl and KBr has a mass of 3.595g, thus the sum of the moles of KCl (x) multiplied by it molar mass (74.5g/mol) and the moles of KBr (y) multiplied by it molar mass (119g/mol) is the total mass of the mixture:

Also, after the conversion of KBr into KCl, the total mass of 3.129 g is only from KCl moles, hence

But the 0.042 moles came from the originals KCl and KBr moles, thus

Now it is possible to propose a system of equations:

Solving the system of equations,

0.010 moles of KBr multiplied it molar mass is

Therefore, the percentage (by mass) of KBr in the original mixture was:

%

there all right good

explanation:

- calcium has greater affinity to bond with electron receptors than hydrogen does and hence, it has the ability to replace hydrogen in most of its compounds.

- lithium has 2 valence electrons in the product because it can make only 1 bond with hydrogen. beryllium has 4 valence electrons in the product because it can only make 2 bonds. it has fewer electrons than neon and can react with electron donors. each hydrogen has 2 valence electrons, the same as helium.

- the covalent bond formed between carbon and hydrogen is polar because carbon is more electronegative than hydrogen and it attracts the bonded electron pair closer to itself, thus giving hydrogen a partial positive charge.

- a hydrogen bond is a relatively weak bond that hydrogen atoms make with the electronegative atoms nitrogen, oxygen or fluorine.

so the best choice is a.) 2 calcium (ca) atoms