Common Polyatomic Ions
| Chemical Name | Chemical Formula | Chemical Name |
|---|---|---|
| acetate | [tex]$C _2 H _3 O _2^{-}$[/tex] | nitrite | [tex]$NO _2^{-}$[/tex] |
| carbonate | [tex]$CO _3^{2-}$[/tex] | ammonium | [tex]$NH _4^{+}$[/tex] |
| hypocarbonite | [tex]$CO ^{2-}$[/tex] | cyanide | [tex]$CN ^{-}$[/tex] |
| hydrogen carbonate (bicarbonate) | [tex]$HCO _3^{-}$[/tex] | hydroxide | [tex]$OH ^{-}$[/tex] |
| chlorite | [tex]$ClO _2^{-}$[/tex] | peroxide | [tex]$O _2^{2-}$[/tex] |
Type the correct answer in the box. Express your answer to three significant figures.
This balanced equation shows the reaction of sodium hydroxide and sulfuric acid: [tex]$2 NaOH + H _2 SO _4 \rightarrow Na _2 SO _4+2 H _2 O$[/tex].
In a laboratory experiment, a student mixes 355 grams of sulfuric acid with an excess of sodium hydroxide. What is the theoretical mass of sodium sulfate produced? Refer to the periodic table and the polyatomic ion resource.
The theoretical mass of sodium sulfate is $\square$ grams.
Answer (2)
Theoretical mass of sodium sulfate produced from the reaction of 355 grams of sulfuric acid is approximately 514 grams. This is calculated based on molar masses and the stoichiometry of the reaction. Rounding to three significant figures, the mass is 514 g.
;
Calculate the molar mass of H 2 S O 4 as 98.076 g/mol .
Calculate the molar mass of N a 2 S O 4 as 142.04 g/mol .
Determine the moles of H 2 S O 4 used: 98.076 g/mol 355 g ≈ 3.619 mol .
Since the mole ratio of H 2 S O 4 to N a 2 S O 4 is 1:1, the mass of N a 2 S O 4 produced is 3.619 mol × 142.04 g/mol ≈ 514 g .
The theoretical mass of sodium sulfate produced is 514 grams.
Explanation
Problem Setup and Goal We are given the balanced chemical equation: 2 N a O H + H 2 S O 4 → N a 2 S O 4 + 2 H 2 O . We know that 355 grams of sulfuric acid ( H 2 S O 4 ) reacts with excess sodium hydroxide ( N a O H ). Our goal is to find the theoretical mass of sodium sulfate ( N a 2 S O 4 ) produced.
Molar Mass of Sulfuric Acid First, we need to calculate the molar mass of sulfuric acid ( H 2 S O 4 ). Using the atomic masses from the periodic table: H = 1.008 g/mol S = 32.06 g/mol O = 16.00 g/mol So, the molar mass of H 2 S O 4 is: M ( H 2 S O 4 ) = 2 ( 1.008 ) + 32.06 + 4 ( 16.00 ) = 2.016 + 32.06 + 64.00 = 98.076 g/mol
Molar Mass of Sodium Sulfate Next, we calculate the molar mass of sodium sulfate ( N a 2 S O 4 ): N a = 22.99 g/mol S = 32.06 g/mol O = 16.00 g/mol So, the molar mass of N a 2 S O 4 is: M ( N a 2 S O 4 ) = 2 ( 22.99 ) + 32.06 + 4 ( 16.00 ) = 45.98 + 32.06 + 64.00 = 142.04 g/mol
Moles of Sulfuric Acid Now, we calculate the number of moles of sulfuric acid ( H 2 S O 4 ) used in the reaction: m o l es ( H 2 S O 4 ) = m o l a r _ ma ss ( H 2 S O 4 ) ma ss ( H 2 S O 4 ) = 98.076 g/mol 355 g ≈ 3.619 mol
Mole Ratio From the balanced equation, the mole ratio between sulfuric acid ( H 2 S O 4 ) and sodium sulfate ( N a 2 S O 4 ) is 1:1. This means that for every 1 mole of H 2 S O 4 that reacts, 1 mole of N a 2 S O 4 is produced.
Moles of Sodium Sulfate Therefore, the number of moles of sodium sulfate ( N a 2 S O 4 ) produced is equal to the number of moles of sulfuric acid ( H 2 S O 4 ) used: m o l es ( N a 2 S O 4 ) = m o l es ( H 2 S O 4 ) = 3.619 mol
Theoretical Mass of Sodium Sulfate Finally, we calculate the theoretical mass of sodium sulfate ( N a 2 S O 4 ) produced: ma ss ( N a 2 S O 4 ) = m o l es ( N a 2 S O 4 ) × m o l a r _ ma ss ( N a 2 S O 4 ) = 3.619 mol × 142.04 g/mol ≈ 514.031 g Rounding to three significant figures, the theoretical mass of sodium sulfate produced is 514 grams.
Final Answer The theoretical mass of sodium sulfate produced is approximately 514 grams.
Examples
In environmental chemistry, calculating the theoretical yield of a reaction is crucial for designing efficient wastewater treatment processes. For instance, determining the amount of gypsum ( C a S O 4 ) that can be precipitated from industrial wastewater by adding lime ( C a ( O H ) 2 ) helps optimize the treatment process. By knowing the stoichiometry of the reaction and the initial amount of reactants, engineers can predict the maximum amount of gypsum that can be removed, ensuring compliance with environmental regulations and minimizing waste. This calculation relies on understanding molar masses, mole ratios, and limiting reactants, similar to the sodium sulfate problem.
