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Tright here are cases when it is required to recognize the percent of an element in a well-known chemical formula. This area will present how to make these calculations.

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There are comes to that tbelow is as well much sodium in our diets. Tbelow are many type of compounds supplied in food assets that contain sodium. Sodium chloride (NaCl, table salt) is the the majority of typically provided compound to include salt to foods items.

What is the percent sodium in the compound NaCl?Tip 1: Calculate the gram formula weight for NaCl.

The gram atomic weight (GAW) for Na is 22.99 g / molThe gram atomic weight (GAW for Cl is 35.45 g / molThe gram formula weight (GFW) for NaCl is 58.44 g / mol

Tip 2 Calculate the % Na in NaCl:From the previous Section Determicountry of Chemical Formulas you must understand the calculation is:


An Example:A biscuit recipe has salt (NaCl) and also baking powder that consists of baking soda (NaHCO3), sodium aluminum sulfate (NaAl(SO4)2 ). Which compound has actually the highest possible percent Na? From the calculation above, we understand NaCl is 39.34 %.

Percent Na in NaHCO3 :



Percent Na in NaAl(SO4)2



Based on the preceding calculations, NaCl has the highest % of Na

Knowing the percent composition of compounds is offered to calculate the grams of an facet in a provided mass of the compound(s). An example of this can be presented utilizing a biscuit recipe.

Baking powder is a mixture containing 30 % baking soda and 24 % sodium aluminum sulfate.

A biscuit recipe calls for 3g of NaCl and 9 g baking powder (NaHCO3 & NaAl(SO4)2)

Because baking powder is 30 % NaHCO3 and 24 % NaAl(SO4)2 , the first calculation would be to multiply 9 g of baking soda by the percent of each chemical to determine the grams of each chemical, NaHCO3 and also NaAl(SO4)2.

Grams of NaHCO3 = 0.30 x 9 g baking powder = 2.7 g NaHCO3

Grams of NaAl(SO4)2 = 0.24 x 9 g baking powder = 2.16 g NaAl(SO4)2

Grams complete from ingredients: = grams from NaCl + grams from NaHCO3 + g from NaAl(SO4)2.

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The calculation is: (making use of the percents calculated above)

Total grams = (0.3934 x 3 g NaCl ) + (0.2738 g x 2.7 g NaHCO3 ) + ( 0.095 x 2.16 g NaAl(SO4)2 ) = 2.125 g Na

The student will certainly encounter calculations such as these in a regular general chemisattempt class.