What mass of potassium hydroxide is required to react completely with 2.70 grams of sulfuric acid to produce potassium sulfate and water?

1) first, write the balanced equation:

2KOH + H₂SO₄ ---> 2H₂O + K₂SO₄

2) convert grams of sulfuric acid to mole using it's molar mass. 

molar mass H₂SO₄= (2 x 1.01) + 32.0 + (4 x 16.0)= 98.0 g/mol

2.70 grams (1 mol/ 98.0 grams)= 0.0276 moles

3) use the mole to mole ratio from the balanced equation to change the moles of sulfuric acid to moles of potassium, hydroxide (KOH).

ration--->2 mol KOH = 1 mol H₂SO₄

0.0276 mol H₂SO4 (2 mol KOH/ 1 mol H₂SO₄)= 0.0551 mol KOH

4) convert moles to grams using the molar mass of KOH

molar mass of KOH= 39.1 + 16.0 + 1.01= 56.1 g/mol

0.0551 mol (56.1 grams/ 1 mol)= 3.09 grams

Because electrons have negligible mass, to account for the mass of the isotope, there must be 16 neutrons, 16 neutrally charged, massive, fundamental particles present in the sulfur nucleus. and thus finally, if we have the 32s2− ion, there are 18 electrons, 16 protons, and 16 neutrons.