Themes > Science > Chemistry > Inorganic Chemistry > Chemical Reaction , Chemical Formulas , Chemical Equation > Chemical Reaction > Determining What Is Reacting > Determining How Much is Produced

Now that you know how to balance equations, you can predict how many moles, grams, etc will be produced in a reaction. The below example will show you how do accomplish this.

Example:

    It is given that 92 grams of Na are produced by the reaction of NaCl + H2 ==> HCl + Na; and they want to know how many grams of HCl are produced.

1. 1st: Balance the equations

    2 NaCl + H2 ==> 2 HCl + 2 Na

2. 2nd: Divide grams by the molar mass of the element to determine the number of moles produced

    92 grams / 23 grams Na = 4 mol Na

3. 3rd: Using the balanced equation, determine the number of moles of product that you are looking for.

    4 mol Na produced / 2 moles Na in equation = x moles HCl produced / 2 moles HCl in equation

4. 4th: Multiply the number of moles of product that you are looking for times the molar mass of the substance

    4 moles HCl * 36.5 grams = 146.0 grams HCl produced


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