A physical properties an aspect of matter that can be observed or measured without changing it. A chemical property may only be observed by changing the chemical identity of a substance.
How many grams of Ca(OH)2 are necessary to prepare 450 mL of 2.25 M solution ?
We have the following data:
m (solute mass) = ? (in grams)
V (volume) = 450 mL → 0.45 L
M (molarity) = 2.25 M (or mol/L)
MM - Molar Mass of Ca(OH)2
Ca = 1*(40.078u) = 40.078 u
O = 2*(15.9994u) = 31.9988 u
H = 2*(1.00794) = 2.01588 u
MM - Molar Mass of Ca(OH)2 = 40.078 u + 31.9988 u + 2.01588 u
MM - Molar Mass of Ca(OH)2 = 74.09268 (≈ 74.09 g/mol)
Now, we apply the data found to the formula of Molarity, let's see:
Will be necessary approximately 75.01 grams of Ca(OH)2
The atoms and molecules in gases are much more spread out than in solids or liquids. They vibrate and move freely at high speeds. A gas will fill any container, but if the container is not sealed, the gas will escape. Gas can be compressed much more easily than a liquid or solid.