Chemistry · Solution and Colloids
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Which ion is present in the highest concentration in a 2 mole/cm3 solution of sodium sulfate?
- A
The hydrogen ion, H+
- B
The hydroxide ion, OH-
- C
The sodium ion, Na+ (aq)
- D
The sulphate ion, SO4-2 (aq).
.Na+ ions will be present in the highest concentration since there are 2 moles of Na+ in each mole of Na2SO4, so the concentration of Na+ is 4 moles/cm3. Therefore, C is the correct answer.
In an aqueous solution of sodium sulfate, H+ ions will be present in very little concentrations due to the dissociation of water. Therefore, A is incorrect.
The concentration of OH- ions will be equal to the concentration of H+ ions (due to the dissociation of water) and will be very small, so B is also incorrect.
Na+ ions will be present in the highest concentration since there are 2 moles of Na+ in each mole of Na2SO4, so the concentration of Na+ is 4 moles/cm3. Therefore, C is the correct answer.
Since there is only 1 mole of SO42- in each mole of Na2SO4, the concentration of SO42- is 2 moles/cm3, so D is also incorrect.
Tagged under Chemistry · Solution and Colloids · 2005