PORTFOLIO

NAME:JOSE PATRICIO R, LAGRATA SECTION:II ST IGNATIUS OF LOYOLASTOICHIOMETRY

THE MOLEWHEN YOU THAT THE MOLECULAR MASS COF CO2 IS 44 AMU YOU ARE REFERRING TO ONE MOLECULE OF CO2. YOU KNOW THAT THE ATOMS AND MOLECULES ARE SO SMALL THAT IT WOULD BE A CHALLENGING TASK TO DETERMINE HOW MANY OF THESE ARE CONTAINED AT THE TIP OF A PENCIL.

FORMULA OR MOLECULAR MASSFORMULA MASS OR MOLECULAR MASS IS DEFINED AS THE MASS IN GRAMS OF A MOLE OF A SUBSTANCE. IT IS THE SUM OF THE ATOMIC MASSES ( N AMU) IN THE MOLECULE.ONE MOLE OF A SUBSTANCE IS EQUAL TO ITS FORMULA MASS EXPRESSED IN GRAMS.THE TERM FORMULA MASS IS USED FOR COMPOUNDS THAT ARE MADE UP OF IONS AND HAVE PRIMARILY IONIC BONDING. YOU CAN WORK OUT THE MOLECULAR MASSES USING THE SAME PROCEDURE.

PERCENTAGE COMPOSITION FROM FORMULASPERCENT IS DEFINED AS PARTS PER HUNDRED.THEN ITS EQUATION IS % OF COMPOSITION=TOTAL MASS OF COMPONENT ELEMENT/MOLAR MASS . 100%=THE ANSWER.

Calculation of percentage compositionThe molecular mass,molar mass,and percentage composition by mass of each element in a compound. The formula can only be obtained after experimentally determining the:a.elements that comprise the compound:b.proportion by mass of the elements in the compound;andc.relative molecular mass of the compound. Empirical formulaThe percent composition of a compound based on experimental data can help determine the ratio of atoms in the compound.the simplest ratio of atoms in a compound formsthe compounds empirical formula.When the relatives number of moles you get is not a whole number,multiply all the numbers by the same small integer.the ff. steps may be used to determine the empirical formula of a compound.1.find the mass in grams of each element present.2.calculate the number of moles of each atom3.divide the number of moles of each element by the smallest number of moles to convert the smallest number to 1.4.multiply the number obtained in step 3 b the smallest integer that will convert all of them to whole numbers.these numbers represent the subscriptMolecular massThe molecular formula of substance is a whole number multiple of its empirical formula.the empirical formula of a compound may or may not be the same as its molecular formula.Mole relationships in a balanced equationA balance equation shows the relative masses of substances,both reactants and product in a chemical reaction.Calculation with balanced equationsMole to mole calculationsYou have learned that the coefficients in a balanced chemical equation can be interpreted as the relative number of moles.each coefficient is related to the others.the coefficients in a chemical reaction are indicative of relationships among reactants and products in terms of amount.

Mole to mass calculationsThe gram is the most convenient unit for me measuring quantities of reactants or products in the laboratory. In order to convert moles to grams or grams to moles you need the molar mass of the given compound.Limiting reactantThere are some reactions that involve excess reactants.these reactants are not used in mass calculation. It is therefore important indentify the limiting reactant.which is the reactant that is consumed first and whichl limits the amount of products that can be formed.