A student obtains a mixture of the chlorides of two unknown metals, X and Z. The percent by mass of X and the percent by mass of
Z in the mixture is known. Which of the following additional information is most helpful in calculating the mole percent of XCl(s) and of ZCl(s) in the mixture?
To determine the mole percent of a mixture ( mole percent of unknown metals = number of mole of each of them divided the total of both the unknown salt × 100) since the percent by mass is know; we the molar mass of X and Z
The percent by mass of X states how many grams of X are in 100 grams of the mixture. Then, we know how many grams of X, Z (we also know its percent) and of Cl ( = 100 - X % - Z %). Taking 100 g of the mixture as a base, we have:
x grams of X
z grams of Z
y grams of Cl
With the molar masses of Z and X (and of Cl) we can transform all masses into moles and then compute the mole percent of XCl(s) and of ZCl(s) in the mixture
As you move down the periodic table in the carbon family, the atomic radius and ionic radius increase while electronegativity and ionization energy decrease. Atom size increases moving down the group because an additional electron shell is added.
