In a mountainous location, the boiling point of pure water is found to be 95 oc. how many grams of sodium chloride must be added to 1 kg of water to bring the boiling point back to 100 oc? . kb for water is 0.512 oc/m. assume i = 2.

285.6 g

Explanation:

The elevation of the boiling point of a solvent that has a solute nonvolatile dissolved is called ebullioscopy, and the change in the temperature may be calculated by the Raoult's law:

ΔT = Kb.W.i

Where ΔT is the temperature change, Kb is the ebullioscopy constant, W is the molality and i is the Van't Hoff factor, which determinates the particles that affect the proper.

The molality is:

W = m1/(M1xm2)

Where m1 is the solute mass (in g), M1 is the molar mass of the solute, and m2 is the mass of the solvent (in kg). Sodium chloride has molar mass equal to 58.5 g/mol (23 of Na and 35.5 of Cl), so:

(100 - 95) = 0.512xWx2

5 = 1.024W

W = 4.883 m

W = m1/(M1xm2)

4.883 = m1/(58.5x1)

m1 = 285.6 g

2fe + 3h2so4 -> fe2(so4)3 + 3h2

it is necessary to balance equations in order to get the proper amount of reactants as well as products in order not to make a miscalculation.

you cannot change the subscripts as that would change the substance itself. for instance, diatomic elements such as h2 only have the subscript two when a gas. another example would be so4, if you were to change the subscript, the element would no longer be sulfate.

we change the coefficients instead as that only changes the number of molecules rather than the substance itself.

hope this !

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