Describe how chemists use mass as a way of getting a precise estimate of the number of entities in a sample.
1 answer:
Answer:
Explanation:
To start with, the mass of a substance is centered on the amount of particles contained in it.
Mass of a substance measure is the same anywhere it is taken.
In chemistry, the concept of mole is used to find the exact estimate of the number of entities in a sample.
A mole of substance is quantity that is used to express the number of particles contained in it.
1 mole of any substance contains the Avogadro's number of particles.
This amount of particles is given as 6.02 x 10²³; the particles can be protons, neutrons, electrons e.t.c.
To find the number of moles;
Number of moles =
Through this, we clearly ascertain the number of entities in a sample given the mass.
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Answer:
Explanation:
The molar mass is the mass of a substance in grams per mole.
To find it, add the mass of each element in the compound. These masses can be found on the Periodic Table.
The compound given is:
The compound has 1 Ca (calcium) and 2 Cl (chlorine).
Mass of Calcium
- The molar mass of calcium is 40.08 g/mol
- There is only one atom of Calcium in CaCl₂, so the number above is what we will use.
Mass of Chlorine
- The molar mass of chlorine is 35.45 g/mol
- There are two atoms of chlorine in CaCl₂, therefore we need to multiply the molar mass by 2.
- 35.45 * 2= 70.9 g/mol
Molar Mass of CaCl₂
- Now, to find the molar mass, add the molar mass of 1 calcium and 2 chlorine.
- 40.08 g/mol + 70.9 g/mol =110.98 g/mol
The molar mass of CaCl₂ is <u>110.98 grams per mole. </u>