Copper

That is not what I get -- though close. How about, show what you did -- clearly, and we can look.

Final Answer: The solubility of copper sulfate at 70°C is approximately 44.4 g per 100 g of water, calculated based on the amount that dissolves in 45.0 g of water. A proportion was set up to find this value. This means that, in saturated conditions, you can dissolve about 44.4 g of copper sulfate in 100 g of water at that temperature. ; Explanation: To find the solubility of copper sulfate ( \text{CuSO}_4 ) at 70°C, follow these steps: Understanding Solubility : Solubility is usually expressed as grams of solute per 100 grams of solvent (water, in this case) at a specific temperature. Given Data : You have 20.0 g of copper sulfate that can dissolve in 45.0 g of water at 70°C. Calculate Solubility : To find the solubility in grams per 100 g of water, first determine how much copper sulfate would dissolve in 100 g of water using a proportion: If 20.0 g of CuSO 4 ​ dissolves in 45.0 g of water, then x g dissolves in 100 g of water. 45.0 g 20.0 g ​ = 100 g x ​ Multiplying both sides by 100 g gives: x = 20.0 g × 45.0 g 100.0 g ​ = 45.0 2000.0 g ​ g ≈ 44.44 g Conclusion : The solubility of copper sulfate at 70°C is approximately 44.4 g per 100 g of water. This means that, at that temperature, about 44.4 g of copper sulfate can dissolve in 100 g of water before reaching saturation. ; Examples & Evidence: This can be compared to other solutes; for example, sodium chloride (table salt) has a higher solubility of around 36 g per 100 g of water at room temperature. Thus, copper sulfate is relatively more soluble at 70°C than sodium chloride is at room temperature. The calculation method using proportions is a standard approach in determining solubility, making the answer reliable.