I need help please and give me an explanation

Determine the number o moles of ions/atoms/particle in the following: 2.50 miles of k2s (let me know how to do)

Two atoms interact with each other as shown by the equation. complete the equation by filling in the missing parts. 1 2 3 4 5 h he li

Assuming complete dissociation of the solute, how many grams of kno3 must be added to 275 ml of water to produce a solution that freezes at -14.5 c? the freezing point for pure water is 0.0 c and k_f is equal to 1.86 c/m