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2.5 g of sulphuric acid is present in 250 cc of solution, what is its ph |
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Answer» MOLAR mass of sulphuric acid is 1*2 + 32+ 4*16 => 98 grams per MOLE. So, 2.5 grams of H2SO4 is 2.5/98 => 0.0255 moles 1 mole of H2SO4 FURNISHES 2 moles of of H+ in AQUEOUS state. So, 0.0255 moles of H2SO4 will furnish 2*0.0255 => 0.051 moles of H+ . Volume of solution is 250 CC or 0.25 litres. Molarity of H+ ion in the solution= (moles of H+)/ litres of solution => 0.051/0.25 => 0.051*100/25 =>0.051 * 4 => Molarity of H+ ions= 0.204 M So, PH of solution = -log (base 10) H+ concentration. => - log (base 10) 0.204 (from calculator log (base 10) 0.204 = -0.69) => -1 * -0.69 => 0.69 Hence the PH of the solution will be 0.69 (approximately) |
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