Question

how many moles of na+ are present in 1 liter of an aqueous solution of Na2SO4 containing 4.76g of the compound? (A:.0670)

Answer 1

Here the chemical is sodium sulfate which has the molar mass 142.04 gm and that is equal to the 1 mole of Sodium Sulfate

Here the ionic reaction is written as

That means 1 mole of will give 2 moles of ion

Or 142.04 gm of will give 46 gm of    (As 1 mole of is 23 gm)

4.76 gm of will give the as

Now we know moles can determined as

here the molar mass of Na is 23 g

and given mass is 1.54g

Now apply the law

Hence the number of moles of are 0.067 .