Any type of medical scientist works.
Molality can be expressed by moles of solute over
kilograms of solvent. The question asks the molality of 0.25m NaCl. 0.25m NaCl
is equal to 0.25 moles of NaCl over 1 kg of water.
Answer:
pH = 3.02
Explanation:
Acetic Acid is a weak acid (HOAc) that ionizes only ~1.5% as follows:
HOAc ⇄ H⁺ + OAc⁻.
In pure water the hydronium ion concentration [H⁺] equals the acetate ion concentration [OAc⁻] and can be determined* using the formula [H⁺] = [OAc⁻] = SqrRt(Ka·[acid]) = SqrRt(1.8x10⁻⁵ x 0.0500)M = 9.5x10⁻⁴M.
By definition, pH = -log[H⁺] = -log(9.5x10⁻⁴) = 3.02
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*This formula can be used to determine the [H⁺] & [Anion⁻] concentrations for any weak acid in pure water given its Ka-value and the molar concentration of acid in solution.
Its FeSO3 or iron(iii)sulfite = Fe2(SO3)3
