A 1.994 g sample of gypsum, a hydrated salt of calcium sulfate, CaSO4, is heated at a temp. above 170 C in a crucible until a constant mass is reached. The mass of anhydrous CaSO4 is 1.577g. what is percent by mas of water in the hydrated calcium sulfate salt
water driven off: 1.994-1.577 g
percentage of water: waterdrivenoff/1.994 * 100
what is Aunilinum?
To find the percent by mass of water in the hydrated calcium sulfate salt, we need to determine the mass of water and the total mass of the hydrated salt.
First, we know the mass of the hydrated salt (gypsum) is 1.994 g, and the mass of anhydrous CaSO4 is 1.577 g. We can find the mass of water by subtracting the mass of anhydrous CaSO4 from the mass of the hydrated salt:
Mass of water = Mass of hydrated salt - Mass of anhydrous CaSO4
= 1.994 g - 1.577 g
= 0.417 g
So, the mass of water in the hydrated calcium sulfate salt is 0.417 g.
To determine the percent by mass of water, we need to divide the mass of water by the total mass of the hydrated salt, and then multiply by 100:
Percent by mass of water = (Mass of water / Total mass of hydrated salt) x 100
= (0.417 g / 1.994 g) x 100
= 20.93%
Therefore, the percent by mass of water in the hydrated calcium sulfate salt is 20.93%.