How to prepare a 5% solution of soda weighing 200 g. Give the calculations of the mass of soda and water.

Let’s calculate the mass of soda needed to prepare 200 g of a 15% solution.
m (Na2CO3) = W • m (solution) / 100% = 5% • 200 g / 100% = 10 g.
The amount of water will be equal to:
m (H2O) = m (solution) – m (Na2CO3) = 200 g – 10 g = 190 g.

One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.