Which of the following statements best describes why a solution of 6.00 g of ca(no3)2? in 30.0 g of water has a greater boiling-point elevation than a solution of 3.00 g of ca(no3)2? in 60.0 g of water?

Boiling-point elevation is a colligative property.

That means, the the boiling-point elevation depends on the molar content (fraction) of solute.

The dependency is ΔTb = Kb*m

Where ΔTb is the elevation in the boiling point, kb is the boiling constant, and m is the molality.

A solution of 6.00 g of Ca(NO3) in 30.0 g of water has 4 times the molal concentration of a solution of 3.00 g of Ca(NO3)2 in 60.0 g of water.:

(6.00g/molar mass) / 0.030kg = 200 /molar mass
(3.00g/molar mass) / 0.060kg =   50/molar mass

=> 200 / 50 = 4.

Then, given the direct proportion of the elevation of the boiling point with the molal concentration, the solution of 6.00 g  of CaNO3 in 30 g of water will exhibit a greater boiling point elevation.

Or, what is the same, the solution with higher molality will have the higher boiling point.

It was ernest rutherford

Answer is: the equilibrium  shifts toward the reactants, to the left side of chemical reaction.it is because lead(ii) nitrate dissociates in water: pb(no₃)₂ → pb²⁺(aq) + 2no₃⁻(aq).according to lechatelier's principle, the position of equilibrium moves to counteract thechange (more lead cations, common ion), the position of equilibrium will move so that the concentration ofproducts decrease and concentration of reactants of chemical reaction increase.read more on -