Page 2: Solving Percentage Concentration Problems

This page presents various examples of stężenie procentowe zadania (percentage concentration problems) with step-by-step solutions.

Problem 1: Calculate the percentage concentration of a solution made by dissolving 425g of sodium chloride in 1.5 kg of water.

Solution:

• ms = 425g (solute mass)
• mw = 1500g (solvent mass)
• mr = 425g + 1500g = 1925g (total solution mass)
• Cp = (425g / 1925g) * 100% = 22.1%

Example: Another problem involves calculating the mass of substance needed to prepare 300g of a 5% solution.

Solution: ms = (Cp * mr) / 100% = (5% * 300g) / 100% = 15g

Highlight: The page emphasizes the importance of clearly identifying given information and the unknown variable in each problem.

The page also covers problems involving density and volume calculations, demonstrating how to integrate these concepts with percentage concentration calculations.

Vocabulary: Gęstość roztworu (solution density) is introduced as an important factor in some percentage concentration problems.

Page 4: Complex Mixing Problems and Ratio Calculations

This final page focuses on advanced stężenie procentowe zadania (percentage concentration problems) involving complex mixing scenarios and calculations using mass ratios.

Key problem types include:

1. Determining mixing ratios to achieve a specific final concentration
2. Calculating concentrations of individual components in a mixture
3. Solving multi-step problems involving successive mixing or dilution

Example: One problem involves determining the mass ratio in which to mix 35% and 20% solutions to obtain a 25% solution.

Solution:

• Let x be the mass of 35% solution and y be the mass of 20% solution
• Set up the equation: (35x + 20y) / (x + y) = 25
• Solve to find the ratio x:y = 1:3

Highlight: The page emphasizes the importance of setting up and solving algebraic equations when dealing with complex mixing problems.

The page also covers problems involving the mixing of three or more solutions, demonstrating how to use weighted averages to calculate final concentrations.

Vocabulary: Stosunek masowy (mass ratio) is introduced as a key concept in solving complex mixing problems.

The page concludes with a reminder of the importance of careful unit conversion and consistent use of mass or volume units throughout multi-step problems.