Final answer:
To find the mass of the undissolved salt at the bottom of the flask, subtract the mass of the water from the total mass of the solution. The mass of the undissolved salt is then obtained by subtracting the mass of the dissolved salt from the initial mass of the salt.
Step-by-step explanation:
To find the mass of the undissolved salt at the bottom of the flask, we need to determine how much of the salt is dissolved and how much remains undissolved. The mass of the salt in the solution can be calculated by subtracting the mass of the water from the total mass of the solution. The mass of the undissolved salt can be obtained by subtracting the mass of the dissolved salt from the initial mass of the salt.
Given that the total mass of the solution is 100 g (50 g of Al₂(SO₄)₃ + 50 g of water), and the mass of the water is 50 g, we can calculate the mass of the dissolved salt as 100 g - 50 g = 50 g.
Therefore, the mass of the undissolved salt at the bottom of the flask is 50 g - 50 g = 0 g. This means that all of the salt has dissolved in the water.