2. Atoms & Elements

How many atoms of H are present in 31.30 grams of formaldehyde (CH2O)?

How many grams are in 11.9 moles of chromium (Cr)?

What is the mass, in grams, of 1.56 × 10^{21} atoms of magnesium (Mg)? (Atomic mass of Mg = 24.3 g/mol)

How many grams are present in 2.50 \times 10^{23} molecules of CaO?

How many grams of H_2O are present in 0.2 moles of H_2O, given that the molar mass of H_2O is 18.01 g/mol?

If you weigh out 0.205 g of salicylic acid (C7H6O3), what is the number of moles of salicylic acid present? (Molar mass of C7H6O3 = 138.12 g/mol)

What is the total mass in grams of 0.75 moles of SO_2?

What is the molar mass of barium hydroxide, Ba(OH)_2?

Which of the following is the mass of one mole of carbon atoms?

What is the molar mass of sulfur dioxide (SO2) in grams per mole?

What is the mass in grams of 5.40 moles of lithium (Li)?

What is the oxygen-to-hydrogen mass ratio in hydrogen peroxide (H2O2)?

What is the molar mass of ammonia (NH_3)?

Given a 0.300 M solution of HF, what concentration of NaF is required to achieve [H3O+] = 2.3 × 10^{-4} M? (Assume Ka for HF = 7.2 × 10^{-4} and that NaF fully dissociates.)

Which of the following is the molar mass of carbon (C)?