Calculate the molecular mass of the nonionic solutes.
64.3 grams of solute in 3.90 x 102 grams of water raises the boiling
point to 100.680 °c.

g/mol

The molecular mass of the nonionic solutes is 124,90 g/m

Explanation:

This is the formula for boiling point elevation.

ΔT = Kb . m

Where ΔT = Tb (solution) - Tb (pure solvent)

Where Kb = the ebullioscopic constant

Where m = molality (moles of solute in 1kg of solvent)

Kb for water is 0,512°C/molal

100,680°C - 100°C = 0,512°C/molal . m

0,680°C = 0,512°C/molal . m

0,680°C /0,512 molal/°C = m

1,32 molality (This are my solute moles in 1kg (1000g) of solvent but I have just 390 g, so let's build the rule of three)

1000 g 1,32 moles

390 g (3,90 g . 1,32 moles) / 1000 g = 0,5148 moles

Molecular mass = g/ mol (mass/moles)

64,3 g /0,5148 moles = 124,90 g/m

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer

"record the time to complete a chemical reaction" would most likely be part of a lab procedure.