The expression to compute molar mass of a solute from the elevation of boiling point of a solvent is (where the various symbols have their usual meanings)

Options

A. `M_2 = (K_b)/(DeltaT_b)m_1/m_2`
B. `M_2 = (DeltaT_b)/(K_b)m_2/m_1`
C. `M_2 = (K_b)/(DeltaT_b)m_1/m_2`
D. `M_2 = (DeltaT_b)/(K_b)m_1/m_2`

Answer

C

Explanation

`DeltaT_b K_b xxm=K_b xx m_2/M_2 xx 1/m_1`
where ma is mass of solute, `m_1` is mass of solvent
`M_2` molar mass of solute, `M_2 = (K_bxxm_2)/(DeltaT_bm_1)`