(Anna Gresham) Stoichiometric Calculations: Instruction
The molar mass of water (H2O) is 18.02 g/mol. Yun needs 0.025 mol H2O for a laboratory experiment. She calculates that she needs 72.0 g H2O for the experiment. Is she correct? Answer without doing any calculations.
no.
Water (H2O) forms when hydrogen gas (H2) and oxygen gas (O2) react according to the equation below: 2H2 +O2 → 2H2O What mass of water forms when 1.45 × 10-3 g O2 react completely? (Molar mass of O2 = 32.00 g/mol; molar mass of H2O = 18.02 g/mol) - 1.63 × 10-3 g - 8.16 × 10-4 g - 1.29 × 10-3 g
1.63 × 10-3 g
What is the mass of 1.84 mol NaCl? Give your answer to the correct number of significant figures. (Molar mass of NaCl = 58.44 g/mol) 1.84 mol NaCl = ______________
108 g NaCl
What mass of oxygen (O2) forms in a reaction that forms 15.90 g C6H12O6? (Molar mass of O2 = 32.00 g/mol; molar mass of C6H12O6 = 180.18 g/mol) 15.90 g C6H12O6 = ______________ g O2
16.94
How many moles of water (H2O) are present in a beaker containing 45.9 g H2O? Give your answer to the correct number of significant figures. (Molar mass of water = 18.02 g/mol) 45.9 g H2O = ______________ mol H2O
2.55
What is the mass of 0.513 mol Al2O3? Give your answer to the correct number of significant figures. (Molar mass of Al2O3 = 102.0 g/mol) 0.513 mol Al2O3 = ______________
52.3 g Al2O3
Consider again the reaction for photosynthesis: 6CO2 + 6H2O → C6H12O6 + 6O2 What mass of water is required to react completely with 157.35 g CO2? (Molar mass of H2O = 18.02 g/mol; molar mass of CO2 = 44.01 g/mol) 157.35 g CO2 = ______________ g H2O
64.43
Consider again the thermite reaction. If 0.0257 g Al react completely, what mass of Fe forms? Use the periodic table to find molar masses. Fe2O3 + 2Al → Al2O3 + 2Fe What mass of Fe forms? Make sure to give your answer with the correct number of significant figures. A total of 0.0257 g Al forms ______________ g Fe.
0.0532
How much water does Yun need for the experiment?
0.45 g
Find the mass that corresponds to each number of moles of iron oxide shown below. 1) A total of 1 mol iron oxide has a mass of 2) A total of 2 mol iron oxide has a mass of 3) A total of 5 mol iron oxide has a mass of
1) 159.7 g 2) 319.4 g 3) 798.5 g
1) How many moles of aluminum oxide (Al2O3) are in a sample with a mass of 204.0 g? - 1.000 - 2.000 - 3.000 2) As the mass of a sample increases, the number of moles present in the sample
1) 2.000 2) increases
For each pair below, select the sample that contains the largest number of moles. 1) Pair A - 2.50 g O2 - 2.50 g N2 2) Pair B - 21.5 g N2 - 15.2 g CO2 3) Pair C - 0.054 g O2 - 0.081 CO2
1) 2.50 g N2 2) 21.5 g N2 3) 0.081 CO2
The overall chemical reaction for photosynthesis is shown below: 6CO2 + 6H2O → C6H12O6 + 6O2 1) What mass of glucose (C6H12O6) can form from 71.89 g CO2? (Molar mass of C6H12O6 = 180.18 g/mol; molar mass of CO2 = 44.01 g/mol) 71.89 g CO2 = ______________ g C6H12O6 2) What mass of oxygen forms from 71.89 g CO2? Use the periodic table to find molar masses. 71.89 g CO2 = ______________ g O2
1) 49.05 2) 52.27
The molar mass of iron oxide (Fe2O3) is 159.7 g/mol. What is the correct way to write the molar mass of iron oxide as a conversion factor?
choice 3
Consider again the reaction for photosynthesis: 6CO2 + 6H2O → C6H12O6 + 6O2. Select the correct mole ratio to complete the calculation shown below.
choice 1
The molar mass of water (H2O) is 18.02 g/mol. Yun needs 0.025 mol H2O for a laboratory experiment. She calculates that she needs 72.0 g H2O for the experiment. Yun's calculation was incorrect because she set up her unit conversion incorrectly. What is the correct way for Yun to set up her calculation?
choice 1
The molar mass of aluminum oxide (Al2O3) is 102.0 g/mol. What is the correct way to write the inverted molar mass of aluminum oxide as a conversion factor?
choice 2
Consider again the thermite reaction. If 0.0257 g Al react completely, what mass of Fe forms? Use the periodic table to find molar masses. Fe2O3 + 2Al → Al2O3 + 2Fe Select the correct setup for this calculation.
choice 3
