Answer:
Mass = 3.6 g
Explanation:
Given data:
Number of atoms of scandium = 4.77×10²² atoms
Mass of arsenic = ?
Solution:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022× 10²³ is called Avogadro number.
one mole = 6.02×10²³ atoms
one mole × 4.77×10²² atoms / 6.02×10²³ atoms
0.08 mol
Mass of scandium
Mass = number of moles × molar mass
Mass = 0.08 mol × 45 g/mol
Mass = 3.6 g
Hey there!
MgCl₂
Find molar mass of magnesium chloride.
Mg: 1 x 24.305
Cl: 2 x 35.453
--------------------
95.211 grams
One mole of magnesium chloride has a mass of 95.211 grams.
We have 2.40 moles.
2.40 x 95.211 = 228.5
To 3 sig figs this is 229.
The mass of 2.40 moles of magnesium chloride is 229 grams.
Hope this helps!
Staining specimen with heavy metal salts (e.g. tungsten, molybdenum) allows you to see the specimen better with higher contrast when electron beam deflects off of your sample.
