An aqueous solution of 17.5g of an unknown covalent compound in 100.0g of water has a freezing point of -1.8C. Calculate the molar mass of the compound. Kf for water is 1.86C/m Solution: Regular freezing point of water is 0C. The freezing point of a solution is -1.8C. ΔTf = -1.8C-0C= -1.8C i=1 because the compound is covalent. Let's now plug and solve for m (molality). -1.8C = -1*1.86 C/m (m) m = 0.9677419 m= moles of solute/ kg solvent The solvent is water. 100.0g= 0.1000kg

A hydrogen atom electron in an excited state with n = 7 drops to a lower energy state with n = 3. What is the wavelength of the light emitted in this transition? Solution: To calculate the wavelength of light emitted when an electron travels from n=7 to n=3, we have to use Rydberg's equation. Where R is the Rydberg's constant, nf is the final energy level, ni is the initial energy level, h is Planck's constant, c is speed of light and λ is wavelength. We will have to take ab