Answer:
Percent loss of water = 25%
Explanation:
Given data:
Mass of hydrated salt = 15.6 g
Mass of anhydrous salt = 11.7 g
Percentage of water lost = ?
Solution:
First of all we will calculate the mass of water in hydrated salt.
Mass of water = Mass of hydrated salt - Mass of anhydrous salt
Mass of water = 15.6 g - 11.7 g
Mass of water = 3.9 g
Now we will calculate the percentage.
Percent loss of water = mass of water / total mass × 100
Percent loss of water = 3.9 g/ 15.6 g × 100
Percent loss of water = 25%
Answer:
4.00 moles
Explanation:
Avogadro´s number is 6.022 x 10²³ molecules, atoms, particles, etc.
Here we are talking of atoms of copper, so 1 mol of copper is equal to 6.022 x 10²³ atoms, and we only need to setup the proportion to find the number of mol in 2.41 x 10²⁴ atoms. ( Think of it like a dozen, avogadro´s is 6.022 x 10²³ )
( 1 mol copper/ 6.022 x 10²³ atoms of copper ) x 2.41 x 10²⁴ atoms
= 4.00 moles
