What is the si unit of pressure and from what units is it derived

The Pascal (symbol: Pa) is the SI derived unit of pressure. It is used to quantify internal pressure, stress, Young's modulus and ultimate tensile strength. It is defined as one Newton per square meter. It is named after the French polymath Blaise Pascal.

The Pascal (Pa) or kilo pascal (kPa) as a unit of pressure measurement is widely used throughout the world and has largely replaced the pounds per square inch.

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%