Concentration And Mole Flashcards
(23 cards)
What is the definition of concentration?
How much of a substance is contained in a specified volume or mass.
What does 1 ppm represent?
1 g in 1,000,000 g or 1 mg in 1 kg or 1 µg in 1 g.
What does 1 ppb represent?
1 g in 1,000,000,000 g or 1 mg per tonne or 1 µg in 1 kg.
How is 1 ppm equivalent to molarity?
1 ppm ≈ 1 mg L-1 ≈ 1 µg mL-1.
How is molarity defined?
Molarity = number of moles of solute per litre of solution.
What is the formula for molarity?
C = n / V.
What does the variable ‘C’ represent in the molarity formula?
Concentration in terms of molarity.
What does the variable ‘n’ represent in the molarity formula?
Number of moles.
What does the variable ‘V’ represent in the molarity formula?
Volume of the solution in litres.
What is the definition of a mole?
The amount of a substance which contains as many elementary entities as there are atoms in 12.0000 g of 12C.
What is Avogadro’s constant (NA)?
6.022 x 10^23.
What does molar mass represent?
The mass of substance containing Avogadro’s number of elementary units of the substance.
What is the relationship between moles and mass?
n = w / M.
What is the formula for calculating the number of moles from mass?
n(mol) = X(g) / M(g mol-1).
What is the atomic number (Z)?
The number of protons in an atom.
What does the atomic mass number (A) represent?
The total number of nucleons in an atom (protons + neutrons).
What are isotopes?
Atoms with the same atomic number but different mass numbers.
How do you calculate the relative atomic mass from isotopes?
Average atomic mass considering natural isotopic abundance.
What is the relative formula mass of calcium carbonate (CaCO3)?
100.0 amu.
What is the molar mass of calcium carbonate in grams per mole?
100.0 g mol-1.
What is the atomic mass of iron (Fe)?
56 amu.
What is the molar mass of iron?
56 g mol-1.
What does the term ‘standard solution’ refer to?
Solutions of known molarity.
