What is a controlled variable

At 40 âc the solution has at 40 â c the solution has blank g of k n o 3 per 100 g of water and it can contain up to blank g of k n o 3 per 100 g of water. at 0 â c the solubility is ~ blank g k n o 3 per 100 g of water, so ~ blank g k n o 3 per 100 g of water will precipitate out of solution.g of kno3 per 100 g of water and it can contain up to at 40 â c the solution has blank g of k n o 3 per 100 g of water and it can contain up to blank g of k n o 3 per 100 g of water. at 0 â c the solubility is ~ blank g k n o 3 per 100 g of water, so ~ blank g k n o 3 per 100 g of water will precipitate out of solution.g of kno3 per 100 g of water. at 0 âc the solubility is ~ at 40 â c the solution has blank g of k n o 3 per 100 g of water and it can contain up to blank g of k n o 3 per 100 g of water. at 0 â c the solubility is ~ blank g k n o 3 per 100 g of water, so ~ blank g k n o 3 per 100 g of water will precipitate out of solution.kno3 per 100 g of water, so ~ at 40 â c the solution has blank g of k n o 3 per 100 g of water and it can contain up to blank g of k n o 3 per 100 g of water. at 0 â c the solubility is ~ blank g k n o 3 per 100 g of water, so ~ blank g k n o 3 per 100 g of water will precipitate out of solution.gkno3 per 100 g of water will precipitate out of solution. a kno3 solution containing 55 g of kno3 per 100.0 g of water is cooled from 40 ∘c to 0 ∘c. what will happen during cooling?

According to each substances heat of fusion, which of the items below requires more heat to be added per gram of substance to go from solid to liquid? silver sulfur water lead

Iwould appreciate if someone could me.