g You are given a 1.25 gram mixture of calcium nitrate and calcium chloride. You dissolve this mixture in 200.0 mL of water and add an excess of 0.300 M silver nitrate. You collect and dry the white precipitate which forms and find it has a mass of 0.535 grams. Calculate the percent calcium chloride by mass in the original mixture.

16.51%

Explanation:

The reaction that takes place is

Meaning that the white precipitate that formed is AgCl. Now we convert 0.535 g of AgCl into moles, using its molar mass:

Then we convert 0.00373 moles of AgCl into moles of CaCl₂, using the stoichiometric coefficients:

We convert moles of CaCl₂ into grams, using its molar mass:

Finally we calculate the percent of CaCl₂ by mass in the original mixture:

there are two significant figures.

c is having 4 valence electrons and is bonded to three hydrogens and one sulphur atom, therefore, the number of bond pair is equal to four. as all the valence electrons are used in forming the bonds so, there is no lone pair left on carbon.

s is having 6 valence electrons and is bonded to one other sulfur atom and one carbon atom, therefore, the number of bond pair is equal to 2. as only two valence electrons are used in forming the bonds so, four electrons are left. therefore, two lone pairs are present on s.