How do you do the criss cross method?

Answer 1

The Criss Cross Method is used to find the general formula for ionic compounds. For monatomic ions, you simply take the absolute value of the ionic charge for the positively charge ion and make it the subscript for the negatively charged ion and vice versa. Example: Al +3 and Cl -1 The 3 becomes the subscript for the chloride ion and the 1 becomes understood for aluminum, to form aluminum chloride: AlCl3 Ionic compounds that form from polyatomic ions can also make use of the criss cross method. The only additional step is to include parenthesis around the polyatomic ion if it has a subscript other than one. Example: Mg+2 and OH-1 The 2 becomes the subscript for the hydroxide ion, but a set of parenthesis is needed to indicate 2 of each the O and the H. The 1 becomes the understood subscript for Mg. Magnesium Hydroxide: Mg(OH)2

Answer 2

The criss-cross method is commonly used in stoichiometry problems to balance chemical equations. Start by writing the reactants and products in a criss-cross pattern with arrows indicating the molar ratios. Multiply coefficients diagonally across the arrows to balance the equation. Repeat the process until all elements are balanced.

Answer 3

Take the two fractions and put them side to side and multiply the numerator and the numerator and the denominator by the denominator and simplify if needed