123 Flashcards
What is the definition of a mole in chemistry?
A mole is the amount of substance that contains the same number of entities as there are atoms in 12 grams of carbon-12.
How many atoms are in one mole of a substance?
Avogadro’s number, which is approximately 6.022 x 10^23 atoms.
What is the molar mass of a substance?
The mass of one mole of a substance, expressed in grams per mole.
What is the formula to calculate the number of moles in a given mass of a substance?
Number of moles = Mass of substance / Molar mass of substance
What is the formula to calculate the mass of a substance given the number of moles?
Mass = Number of moles x Molar mass of substance
True or False: The molar mass of a compound is the sum of the atomic masses of all the atoms in the compound.
True
What is the molarity of a solution?
The number of moles of solute per liter of solution.
What is the formula to calculate molarity?
Molarity = Number of moles of solute / Volume of solution in liters
What is the relationship between molarity, volume, and number of moles of solute in a solution?
Molarity = Number of moles of solute / Volume of solution in liters
What is the relationship between mass, molar mass, and number of moles of a substance?
Mass = Number of moles x Molar mass of substance
How many liters of a 0.5 M solution contain 1 mole of solute?
2 liters
What is the volume of 2 moles of a gas at STP?
44.8 liters
How many moles are in 36 grams of water?
2 moles
How many grams are in 0.5 moles of NaCl?
29.5 grams
What is the molar mass of H2O?
18 grams per mole
What is the molar mass of CO2?
44 grams per mole
What is the molarity of a solution containing 0.2 moles of NaCl in 500 mL of solution?
0.4 M
How many grams of sulfur are in 2 moles of sulfur?
64 grams
What is the volume of 3 moles of a gas at STP?
67.2 liters
How many molecules are in 2 moles of water?
1.204 x 10^24 molecules
What is the molar mass of CaCO3?
100 grams per mole
What is the mass of 0.25 moles of MgCl2?
29.5 grams
What is the molarity of a solution containing 0.5 moles of KCl in 250 mL of solution?
2 M
How many moles are in 72 grams of CO2?
1.5 moles
