Find the amount of solute present in the following solutions .250cm³ of 0.20mol dm³ solutions of sulphuric acid. And find the amount of solute present in the following solution. Ammonia is bought as "880 Ammonia "(a solution of density 0.880 g cm-³ ),which contains 245.0g Ammonia per dm³ of solutions. What volume of the concentrated would you need to prepare 1.odm³ of 2.0mol dm-³Ammonia solutions?
1. For the first solution:
Amount of solute = volume of solution x concentration of solution
Amount of solute = 0.250 cm³ x 0.20 mol dm³
Amount of solute = 0.050 mol
2. For the second solution:
Concentration of "880 Ammonia" solution = 245.0 g dm-³
Density of "880 Ammonia" solution = 0.880 g cm-³
Volume of concentrated ammonia solution needed:
Volume = Amount of solute / Concentration of solution
Volume = 1.0 dm³ x 2.0 mol dm-³ / 245.0 g dm-³
Volume = 0.00816 dm³ = 8.16 cm³
Therefore, you would need to use 8.16 cm³ of the concentrated "880 Ammonia" solution to prepare 1.0 dm³ of 2.0 mol dm-³ Ammonia solution.