Calculate the molality of a solution formed by dissolving 34.8 g of lii in 500.0 ml of water. calculate the molality of a solution formed by dissolving 34.8 g of lii in 500.0 ml of water. 0.520 m 0.260 m 0.254 m 0.696 m 0.130 m

First step is to find the number of moles in 34.8 gm of LiI:
From the periodic table: molar mass of Li = 6.941 while that of I = 126.9
Molar mass of LiI = 6.941 + 126.9 = 133.841
Number of moles = mass/molar mass = 34.8/133.841 = 0.26 moles

Second step is to calculate the molality:
molality = number of moles of solute / kilogram of solvent
At STP: 1L of water = 1Kg, thus, 500 ml of water = 0.5 kg
molality = 0.26/0.5 = 0.52 mole/Kg

All the elements are arranged by melting points on the periodic table. in row they go from metals to gasses. in the row from sodium to argon, sodium is more reactive than the one on its right, magnesium.