Chemical Reactions and Stoichiometry
What are the reactants in the following equation: HCI(aq) + NaHCO;(aq)→ CO2(g) + H,O(1) + NaCI(aq)
HCI, NaHCO3
A cereal contains 11.0 grams of sucrose (C12H22011) per 60.0 grams of cereal. How many grams of cereal must be eaten to consume 0.0424 moles of sucrose?
Solution: (0.0424 mol C12H22011) X ((342.34 g C12H22011) / (1 mol C12H201)) X (60.0 g cereal)) / ((11.0 g C12H2201)) = 79.2 g cereal
How many moles of propylene (C3H6) are in 25.0 g of the substance?
Solution: (25.0 g) X ((1 mol C3Hs) / (42.09 g C3H6) = 0.594 mol
Balance the following chemical equation (if necessary): 2 C3H6(g) + 9 02(g) → 6 CO2(g) + 6 H20(g)
Solution: 2 C3H6(g) + 9 O2(g) → 6 CO2(g) + 6 H20(g)
Balance the following chemical equation (if necessary): 2 H2SO4(aq) + Pb(OH)4(s) → Pb(SO4)2(s) + 4 H20 (l)
Solution: 2 H2SO4 (aq) + Pb(OH)4(s) → Pb(SO4)2(s) + 4 H20(l)
Balance the following chemical equation (if necessary): 3 ZnS(s) + 2 AIP (s) → Al2S3(s) + ZnąP2(s)
Solution: 3 ZnS(s) + 2 AIP(s) → Al2S3(s) + Zn3P2(s)
Which of the following reactions is a double displacement reaction?
Solution: A double displacement reaction involves two ionic compounds that react and form two new ionic compounds. The cations from the reactants "switch" places. The correct answer is HCI (aq) + NaOH (aq) H,O (I) + NaCl (aq).
Balance the following chemical equation (if necessary) for the combustion reaction of glucose: C6H1206(s) + 6 O2(g) → 6 CO2(g) + 6 H20(g)
Solution: C6H1206(s) + 6O2(g) → 6CO2(g) + 6H20(g)
What is the concentration of a solution made with 0.150 moles of KOH in 400.0 mL of solution?
Solution: The following solution may contain one or more values that are different from the problem provided to you, however, the steps to solve the problem are the same. Molarity (M) is the concentration of a solution expressed as the number of moles of solute per liter of solution (mol/L). Since the problem provided moles and mL, convert the volume and divide to find the molarity. (0.150 mol) / ((400.0 mL) X ((1 L) / (1000 mL))) = 0.375 M
Calculate the mass, in grams, of 202 atoms of iron, Fe (1 mol of Fe has a mass of 55.85 g).
Solution: The following solution may contain one or more values that are different from the problem provided to you, however, the steps to solve the problem are the same. The mass of a substance can be calculated from its number of atoms using Avogadro's number and its molar mass. (202 atoms of Fe) X ((1 mol Fe) / (6.022 × 10^23 atoms Fe)) X ((55.85 g Fe) / (1 mol Fe) = 1.8 x 10-^20 g Fe
Determine the molar mass of CH3OCH3.
Solution: The following solution may contain one or more values that are different from the problem provided to you, however, the steps to solve the problem are the same. The molar mass is the mass of one mole of each atom in a molecule or formula unit. This can be calculated by adding the molar mass of each atom in the molecule or formula unit. For example, consider CH3OCH3. The molar mass of carbon is 12.01 g, the molar mass of hydrogen is 1.01 g, and oxygen has a molar mass of 16.00 g. There are six moles of hydrogen, two moles of carbon, and one mole of oxygen in a mole of each molecule. (12.01 g x 2) + (1.01 g × 6) + 16.00 g = 46.08 g
Determine the number of atoms in 51.0 grams of sodium, Na. (The mass of one mole of sodium is 22.99 g.)
Solution: The following solution may contain one or more values that are different from the problem provided to you, however, the steps to solve the problem are the same. The number of atoms of a substance can be calculated using Avogadro's number and its molar mass. (51.0 g Na) X ((1 mol Na) / (22.99 g Na)) X ((6.022 x 1023 atoms) X (1 mol Na)) = 1.34 × 10^24 atoms
Determine the mass in grams of 3.00 x 1021 atoms of arsenic. (The mass of one mole of arsenic is 74.92 g.)
Solution: The following solution may contain one or more values that are different from the problem provided to you, however, the steps to solve the problem are the same. The number of moles of a substance can be calculated using Avogadro's number. Then, the mass can be calculated using the molar mass. (3.00 x 1021 atoms of As) X ((1 mol As) / (6.022 x 1023 atoms of As)) X ((74.92 g As) X (1 mol As)) = 0.373 g As
Determine the formula weight of KBr.
Solution: The formula weight is the mass of one molecule or formula unit. This can be calculated by adding the atomic mass of each atom. The atomic mass of potassium is 39.10 amu and the atomic mass of bromine is 79.90 amu. 39.10 amu + 79.90 amu = 119.00 amu
Which of the following represents the generic form of a double-displacement reaction?
Solution: The generic form of a double displacement reactions, also called double replacement reaction, occurs when parts of two ionic compounds being exchanged, making two new compounds. Double Displacement Reaction: AX + BY → AY + BX
Which of the following represents the generic form of a single-displacement reaction?
Solution: The generic form of a single displacement reactions, also called a single replacement reaction, occurs when a single element displaces, or substitutes, another element in a compound. Single Displacement Reaction: A + BX → AX + B
Determine the molar mass of Al2(SO4)3 • 5H20.
Solution: The molar mass is the mass of one mole of each atom in a molecule or formula unit. This can be calculated by adding the molar mass of each atom in the molecule or formula unit. The molar mass of aluminum is 26.98 g, the molar mass of sulfur is 32.06 g, oxygen has a molar mass of 16.00 g, and hydrogen has a molar mass of 1.01 g. There are two moles of aluminum, three moles of sulfur, seventeen moles of oxygen, and ten moles of hydrogen in each formula unit of Al2(SO4)3 • 5H2O. ((26.98 g x 2) + (3 × (32.06 g + (4 × 16.00 g))) + (5 × ((2 × 1.01 g) + 16.00 g)) = 432.24 g
Determine the molar mass of C6H12O6.
Solution: The molar mass is the mass of one mole of each atom in a molecule or formula unit. This can be calculated by adding the molar mass of each atom in the molecule or formula unit. The molar mass of carbon is 12.01 g, the molar mass of hydrogen is 1.01 g, and oxygen has a molar mass of 16.00 g. There are six moles of carbon, twelve moles of hydrogen and six moles of oxygen per molecule of C6H1206. (6 x 12.01 g) + (12 × 1.01 g) + (6 × 16.00 g) = 180.18 g
Determine the molar mass of Cr3(PO4)2.
Solution: The molar mass is the mass of one mole of each atom in a molecule or formula unit. This can be calculated by adding the molar mass of each atom in the molecule or formula unit. The molar mass of chromium is 52.00 g, the molar mass of phosphorus is 30.97 g, and oxygen has a molar mass of 16.00 g. There are three moles of chromium, two moles of phosphorus and eight moles of oxygen per formula unit of chromium phosphate, Cr3(PO4)2. (3 x 52.00 g) + (2 × (30.97 g + (4 × 16.00 g))) = 345.94 g
What type of reaction is represented by the following equation: 2Na(s) + Cl2(g) → 2NACI(s)
Solution: This is a combination reaction, involves two compounds reacting to form one new compound. This type of reaction is also known as a synthesis reaction.
What type of reaction is represented by the following equation: CoCl,(aq) + 2NaOH(aq) → Co(OH)2(s) + 2NACI(aq)
Solution: This is a precipitation reaction,which involves the formation of an insoluble solid and an aqueous solution.
