1.8 Formula mass and the mole concept  (Page 7/11)

Calculate the molar mass of each of the following:

(a) S ₈

(b) C ₅ H ₁₂

(c) Sc ₂ (SO ₄ ) ₃

(d) CH ₃ COCH ₃ (acetone)

(e) C ₆ H ₁₂ O ₆ (glucose)

Calculate the empirical or molecular formula mass and the molar mass of each of the following minerals:

(a) limestone, CaCO ₃

(b) halite, NaCl

(c) beryl, Be ₃ Al ₂ Si ₆ O ₁₈

(d) malachite, Cu ₂ (OH) ₂ CO ₃

(e) turquoise, CuAl ₆ (PO ₄ ) ₄ (OH) ₈ (H ₂ O) ₄

Calculate the molar mass of each of the following:

(a) the anesthetic halothane, C ₂ HBrClF ₃

(b) the herbicide paraquat, C ₁₂ H ₁₄ N ₂ Cl ₂

(c) caffeine, C ₈ H ₁₀ N ₄ O ₂

(d) urea, CO(NH ₂ ) ₂

(e) a typical soap, C ₁₇ H ₃₅ CO ₂ Na

Determine the number of moles of compound and the number of moles of each type of atom in each of the following:

(a) 25.0 g of propylene, C ₃ H ₆

(b) 3.06 $\times$ 10 ⁻³ g of the amino acid glycine, C ₂ H ₅ NO ₂

(c) 25 lb of the herbicide Treflan, C ₁₃ H ₁₆ N ₂ O ₄ F (1 lb = 454 g)

(d) 0.125 kg of the insecticide Paris Green, Cu ₄ (AsO ₃ ) ₂ (CH ₃ CO ₂ ) ₂

(e) 325 mg of aspirin, C ₆ H ₄ (CO ₂ H)(CO ₂ CH ₃ )

Determine the mass of each of the following:

(a) 0.0146 mol KOH

(b) 10.2 mol ethane, C ₂ H ₆

(c) 1.6 $\times$ 10 ⁻³ mol Na ₂ SO ₄

(d) 6.854 $\times$ 10 ³ mol glucose, C ₆ H ₁₂ O ₆

(e) 2.86 mol Co(NH ₃ ) ₆ Cl ₃

Determine the number of moles of the compound and determine the number of moles of each type of atom in each of the following:

(a) 2.12 g of potassium bromide, KBr

(b) 0.1488 g of phosphoric acid, H ₃ PO ₄

(c) 23 kg of calcium carbonate, CaCO ₃

(d) 78.452 g of aluminum sulfate, Al ₂ (SO ₄ ) ₃

(e) 0.1250 mg of caffeine, C ₈ H ₁₀ N ₄ O ₂

Determine the mass of each of the following:

(a) 2.345 mol LiCl

(b) 0.0872 mol acetylene, C ₂ H ₂

(c) 3.3 $\times$ 10 ⁻² mol Na ₂ CO ₃

(d) 1.23 $\times$ 10 ³ mol fructose, C ₆ H ₁₂ O ₆

(e) 0.5758 mol FeSO ₄ (H ₂ O) ₇

The approximate minimum daily dietary requirement of the amino acid leucine, C ₆ H ₁₃ NO ₂ , is 1.1 g. What is this requirement in moles?

Determine the mass in grams of each of the following:

(a) 0.600 mol of oxygen atoms

(b) 0.600 mol of oxygen molecules, O ₂

(c) 0.600 mol of ozone molecules, O ₃

A 55-kg woman has 7.5 $\times$ 10 ⁻³ mol of hemoglobin (molar mass = 64,456 g/mol) in her blood. How many hemoglobin molecules is this? What is this quantity in grams?

Determine the number of atoms and the mass of zirconium, silicon, and oxygen found in 0.3384 mol of zircon, ZrSiO ₄ , a semiprecious stone.

Determine which of the following contains the greatest mass of hydrogen: 1 mol of CH ₄ , 0.6 mol of C ₆ H ₆ , or 0.4 mol of C ₃ H ₈ .

Determine which of the following contains the greatest mass of aluminum: 122 g of AlPO ₄ , 266 g of Al ₂ C1 ₆ , or 225 g of Al ₂ S ₃ .

Diamond is one form of elemental carbon. An engagement ring contains a diamond weighing 1.25 carats (1 carat = 200 mg). How many atoms are present in the diamond?

The Cullinan diamond was the largest natural diamond ever found (January 25, 1905). It weighed 3104 carats (1 carat = 200 mg). How many carbon atoms were present in the stone?

One 55-gram serving of a particular cereal supplies 270 mg of sodium, 11% of the recommended daily allowance. How many moles and atoms of sodium are in the recommended daily allowance?

A certain nut crunch cereal contains 11.0 grams of sugar (sucrose, C ₁₂ H ₂₂ O ₁₁ ) per serving size of 60.0 grams. How many servings of this cereal must be eaten to consume 0.0278 moles of sugar?

A tube of toothpaste contains 0.76 g of sodium monofluorophosphate (Na ₂ PO ₃ F) in 100 mL.

(a) What mass of fluorine atoms in mg was present?

(b) How many fluorine atoms were present?

Which of the following represents the least number of molecules?

(a) 20.0 g of H ₂ O (18.02 g/mol)

(b) 77.0 g of CH ₄ (16.06 g/mol)

(c) 68.0 g of CaH ₂ (42.09 g/mol)

(d) 100.0 g of N ₂ O (44.02 g/mol)

(e) 84.0 g of HF (20.01 g/mol)