Answer: Theoretical mass of sodium sulphate ( 
) is 514.118 grams.
Explanation: For a given reaction,
As NaOH is used in excess, therefore it is an excess reagent and 
is a limiting reagent as the quantity of the product will depend on it.
We are given 355 grams of .
Molar mass of = 98.079 g/mol
Molar mass of = 142.04 g/mol
1 mole of is producing 1 mole of , so
98.079 g/mol of will produce 142.04 g/mol of
355 grams of will produce = 
of
Mass of = 514.118 grams
The untrue statement is that they high melting points.
The covalent compounds are the compounds exhibiting strong intra-molecular bonds. This is due to the tightness of the atoms within the covalent molecules. The force of attraction between the individual molecules in a covalent compound seems to be weak. The covalent compounds exhibit weak intermolecular forces that hold the atoms together due to this they have a low melting point.
The type of atoms present in the chemical compound and the proportion or how many specific atoms are respect to other atoms in the chemical compound.
