Stoichiometry

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= Stoichiometry =

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1. (s)--the substance is in a solid state 2. (g)--the substance is in a gaseous state 3. (l)--the substance is in a liquid state 4. (aq)--the substance has been dissolved in an aqueus solution (which is to say, water) 5. →--"yields" and is used to indicate the result of the reaction. 6. ↔--that the reaction is reversible 7. ∆ (over the reaction arrow)--the application of heat to the reactants 1. The first step in the inspection method o balancig equatios involves counting the number of each atom in the equation on the reactant side and then on the product side. 2. The next step is to balance one atom at a time by adding a coefficient where needed and recounting the atoms. Adding coeffidients and recounting continue until the same number of atoms is present on each side of the arrow. Chemists find the process simpler if they balance the most complex molecule first, leaving the simple compounds and elements until last. Also, elements that appear in more thn one compound on either threactant or product side are left to the end. Finally, it is faster to balance groups of atoms, such as the sulfate or nitrate ions discussed later, as if they were induvidual atoms. 1. Assume that the total quantity in mass of the unknow substance is 100g. 2. Multiply 100 by the percentage of every element and get the mass of every element. 3. Calculate the number of moles of each element in the compound using the mass numbers. 4. Divide the numver of moles of eh element obtained in last step by the smallest value found to obtain whole-number sucscripts fot the empirical formula (Note that, if last step does ot give whole numbers, the decimal portion of each number will be close ta a rational fraction. In this situation, multiply each item of the data by the denominator of the rational fraction to remove the fraction and end up with a whole-number subscript for the empirial formula.) The definition of mole ratio: The ratio of moles of one reactant or product to the moles of another reactant or product in the balanced equation for a chemical reaction.
 * Symbols used in chemical equations
 * Balance reactions
 * Calculate empirical formula (molecular formula) from percent mass
 * Mole diagram[[image:Untitled-2.jpg width="800" height="1035"]]
 * Use balanced reaction and mole ratios dilution, molarity

The mole ratio compares the number of moles of one substance in a chemical equation with another substance, usually on the opposite side of the equation. The steps: 1.Determine which elements or compounds are in your reaction and write the skeleton equation. 2.Determine the coefficients necessary to balance the number of atoms on each side of the equation. 3.Notice that all the terms on the right side now have coefficients. 4. Calculate the mole ratio. Start with the quantities given to you in the problem. Molarity:is a measure of the concentration of a solute in a solution, or of any molecular, ionic, or atomic species in a given volume. Molarity= Moles of solute/ Volume of solution in Liters

In chemistry, the limiting reagent, also known as the "limiting reactant", is the chemical that determines how far the reaction will go before the chemical in question gets "used up", causing the reaction to stop. The chemical of which there are fewer moles than the proportion requires is the limiting reagent.
 * Limiting reagent / percent yield

The formula for limiting reagent: In chemistry, yield, also referred to as chemical yield and reaction yield, is the amount of product obtained in a chemical reaction. The absolute yield can be given as the weight in grams or in moles (molar yield). The fractional yield, relative yield, or percentage yield, which serve to measure the effectiveness of a synthetic procedure, is calculated by dividing the amount of the obtained product in moles by the theoretical yield in moles: Given the following equation:8 H2+S8--->8H2S,write the following molar ratios: a) H2/H2S b)H2/S8 c) H2S/S8
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