Final answer:
The equivalent weight of Na2CO3 is calculated by dividing its formula weight by its valence. The formula weight is 105.99 amu and, assuming Na2CO3 acts with a valence of 2, its equivalent weight is 52.995 amu.
Step-by-step explanation:
To calculate the equivalent weight for Na2CO3 (sodium carbonate), we first need to determine its formula weight. The formula weight is the sum of the atomic weights of all the atoms in the compound's chemical formula, and equivalent weight involves dividing that formula weight by the valence of the compound, which is determined by its ability to react with other substances.
The atomic weights for each element are as follows (rounded to two decimal places):
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- Na (Sodium): 22.99 amu
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- C (Carbon): 12.01 amu
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- O (Oxygen): 16.00 amu
Since there are two sodium atoms, one carbon atom, and three oxygen atoms in sodium carbonate, the calculation would look like this:
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- 2 x 22.99 amu (for Na)
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- 1 x 12.01 amu (for C)
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- 3 x 16.00 amu (for O)
Add these together to determine the formula weight:
2 x 22.99 + 1 x 12.01 + 3 x 16.00 = 105.99 amu
To find the equivalent weight, we divide the formula weight by the number of moles of electrons transferred per mole of compound in a chemical reaction. For Na2CO3, in a typical reaction where it acts as a source of CO32-, the valence is 2.
The equivalent weight of Na2CO3 is therefore:
105.99 amu / 2 = 52.995 amu
The equivalent weight of Na2CO3 to four significant figures is 52.995 amu.