2. Atoms & Elements

Which of the following statements correctly describes the mass of exactly 1 mole of an element?

How many atoms are present in one mole of atoms?

How many atoms are present in one mole of carbon?

How many moles of Cu are present in 1.48 × 10^{25} Cu atoms?

A mole is defined as the number of atoms in exactly 12 grams of which isotope?

What is the total number of molecules of hydrogen in 0.25 mole of hydrogen gas (H_2)?

How many moles of carbon (C) are present in 440 mg of carbon dioxide (CO_2)?

How many atoms are present in 1 mole of copper (Cu)?

A sample contains 18.0 g of water (H_2O). How many moles of molecules are present in this sample?

How many moles of water (H2O) are present in 75.0 g of H2O?

How many atoms of nitrogen are present in 10 g of NH_4NO_3?

Why do chemists use the mole as a unit in chemical calculations?

A student titrates 25.00 mL of HCl solution with 0.100 M NaOH. If it takes 32.50 mL of NaOH to reach the endpoint, how many moles of HCl were present in the original 25.00 mL of acid?

How many atoms are present in one mole of a substance?

How many molecules are present in 25 grams of NH_3?