is the following sentence true or false?
To determine the number of representative particles in a compound, you count the molecules by viewing them under a microscope.__true______
Most molecules are too small to see with an ordinary microscope.
Can molar masses be calculated directly from atomic masses expressed in grams.
yes.
Atomic masses of
C= 12
O = 16
molar mass of
CO2 = 12 + (2x16) = 12 + 32 = 44 g/mol.
The sentence "To determine the number of representative particles in a compound, you count the molecules by viewing them under a microscope" is false.
Most molecules are too small to be seen with an ordinary microscope, so they cannot be counted directly by viewing them.
To determine the number of representative particles in a compound, we use Avogadro's number, which is 6.022 × 10^23 particles/mol. This number represents the number of atoms, molecules, or other particles in one mole of a substance.
Regarding the second question, yes, molar masses can be calculated directly from atomic masses expressed in grams.
For example, let's calculate the molar mass of carbon dioxide (CO2). The atomic mass of carbon (C) is 12 grams per mole, and the atomic mass of oxygen (O) is 16 grams per mole.
To calculate the molar mass of CO2, you simply add the atomic masses of the atoms in the molecule: 12 + (2 × 16) = 44 grams per mole.
So the molar mass of carbon dioxide (CO2) is 44 grams per mole.