2. Atoms & Elements

How many moles of CO_2 are present in a 220.-gram sample of CO_2, given that the gram-formula mass of CO_2 is 44 g/mol?

Which of the following steps correctly converts 18.0 grams of water (H_2O) to the number of molecules?

In the context of the mole concept, 12.0 grams of carbon-12 represents which of the following?

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

How many carbon atoms are present in 1.00 mole of methane (CH_4)?

If you have 1 mole of NaCl, how many NaCl formula units does it contain?

How many moles of carbon are present in 4.1 × 10^{24} atoms of carbon?

How many moles of CaCl_2 are present in 250 mL of a 3.0 M CaCl_2 solution?

A solution is prepared by dissolving potassium fluoride (KF) in 347 g of water to make a 0.175 molal (m) KF solution. How many moles of KF are present in the solution?

How many chlorine atoms are present in 29 molecules of chloroform (CHCl_3)?

How many moles of beryllium atoms are present in 36 g of Be? (Atomic mass of Be = 9 g/mol)

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

How many molecules are present in 2.30 grams of NH_3?

How many atoms are present in 3.50 moles of calcium (Ca)?

How many moles are present in 23.4 g of CaCl_2?