The mole is the unit for amount of substance. The number of particles in a substance can be found using the Avogadro constant. The mass of product depends upon the mass of limiting reactant.
The value of the Avogadro constant is 6.02 x 1023. This means that there are 6.02 x 1023…what?
Atoms in 1 g of H2
Atoms in 1 mol of an element
Atoms in 1 g of carbon
How many atoms are there in 1 mol of water molecules (H2O)?
(The value of the Avogadro constant is 6.02 x 1023)
6.02 x 1023
1.204 x 1024
1.806 x 1024
What is the equation showing the number of moles present in a substance?
Number of moles = mass × Mr
Number of moles = Mr ÷ mass
Number of moles = mass ÷ Mr
What is the mass of 4 mol of carbon dioxide molecules? (Mr of carbon dioxide = 44)
A piece of sodium is added to a beaker of water. The sodium completely reacts, producing hydrogen gas. Which substance is in excess in this reaction?
A sample of the compound hydrogen sulfide contained 0.05 mol of hydrogen atoms and 0.025 mol of sulfur atoms. What is the empirical formula of hydrogen sulfide?
What is the mass of 3 mol of N2O5 molecules? Use these Ar values: N = 14 and O = 16
A sample of a compound contains 0.20 mol of carbon atoms and 0.80 mol of hydrogen atoms. What is its empirical formula?
In an experiment, 0.12 g of magnesium reacts with oxygen to make 0.28 g of magneisum oxide. How many moles of oxygen molecules took part in the reaction? Use these Ar values: Mg = 24 and O = 16.
2.4 g of carbon reacts with 0.6 g of hydrogen to make a compound. What is the empirical formula of the compound? The mass of one mole of carbon atoms is 12 g, and the mass of one mole of hydrogen atoms is 1 g.