The sodium sulfate solution was made by dissolving 28.4 g of sodium sulfate in water to make 250 cm³ - Edexcel - GCSE Chemistry Combined Science - Question 2 - 2020 - Paper 1

To find the concentration of the sodium sulfate solution, we can use the formula:

1. Convert volume from cm³ to dm³:

   • Since 1 dm³ = 1000 cm³, we get:
   250 ext{ cm}^3 = rac{250}{1000} ext{ dm}^3 = 0.25 ext{ dm}^3

2. Calculate the concentration:

   • Use the mass of sodium sulfate:
   ext{Concentration} = rac{28.4 ext{ g}}{0.25 ext{ dm}^3} = 113.6 ext{ g dm}^{-3}

3. Round the answer to three significant figures:

   • Thus, the final concentration is:
   $$ext{Concentration} = 114 ext{ g dm}^{-3}$$