Mendeleev’s arrangement of elements in the periodic table was based on the observations and experiments of his predecessors who studied mass and properties of elements. true or false?

Mendeleev’s arrangement of elements in the periodic table was based on the observations and experiments of his predecessors who studied mass and properties of elements is TRUE.

Explanation:

In Mendeleev’s periodic table, elements were ordered according to their atomic masses. This is the fundamental property on which Mendeleev's periodic table is based on.

Mendeleev has also formulated a periodic law which states that the properties of elements are the "periodic function of their atomic masses". However, due to the anomalies that were created in his periodic table, we don't use this periodic table and prefer modern periodic table that is based on property of atomic number.

1. for the first question, we must find the mass of the anhydrous salt, mgso₄. the molar mass for mgso₄·7h₂o is 246.47 g/mol, while that of mgso₄ is 120.37 g/mol.7.834 g mgso₄·7h₂o * 1 mol mgso₄·7h₂o/246.47 g * 1 mol mgso₄/1 mol mgso₄·7h₂o * 20.37 g mgso₄/mol = 0.647 g mgso₄

2. mass of water = mass of sample - mass of anhydrous salemass of water = 7.834 - 0.647 = 7.19 gpercent water in hydrate = 7.19/7.834 * 100 = 91.74%