STOICHIOMETRY WORKSHEET 5 MASS-MOLES-ATOMS/MOLECULES 1. Fill in the tables (1 mole = 6.022 * 10%). Substance Mass Moles Atoms Silicon 0.456 lb Boron 8.2 mol Manganese ug 3.97 X 1024 Aluminum 0.0628 kg Carbon 8 5.9 mol Chlorine Іь 4.920 X 1022 Substance Mass Moles Molecules 5.928 Ammonium Carbonate Sulfuric Acid g 0.987 mol Sodium Phosphate Hg 2.58 x 1023 AceticAcid 0.0628 kg 8 1.46 mol Diphosphorus Heptoxide Copper(II) Nitrite lb 7.55 X 1021 25 DATE: NAME: AMMONIUM CARBONATE 1. What is the molar mass of ammonium carbonate? WORKSHEET 5 2. What is the mass percent of each element? 3. How many moles of oxygen (O) are in 9.85 g of ammonium carbonate? 4. How many hydrogen (H) atoms are in 0.546 lb of ammonium carbonate? 5. How many grams of nitrogen (N) are in a mass of ammonium carbonate that contains 1.23 x 104 carbon atoms? 6. How many grams of ammonium carbonate are in the previous problem? 26 NAME: DATE: SODIUM PHOSPHATE 1. What is the molar mass of sodium phosphate? WORKSHEET 5 2. What is the mass percent of each element? 3. How many sodium (Na) ions are in 5.55g of sodium phosphate? 4. How many grams of oxygen (O) are in a mass of sodium phosphate that contains 3.69 moles of phosphorus? 5. How many grams of phosphorus are in 1.00 X 10 sodium phosphate molecules? 6. How many oxygen atoms are 4.75 moles of sodium phosphate? 27 DATE: NAME: TURQUOISE: CUAL (PO..(OH)8.4H20 1. How many total atoms are in 5.00 g of turquoise? WORKSHEET 5 2. How many water molecules are in a sample of turquoise with a mass of 10.0 g? 3. How many milligrams of turquoise contain 3.75 X 102 atoms of oxygen? 4
The Correct Answer and Explanation is :
This worksheet covers multiple stoichiometry problems involving moles, mass, atoms, and molecules. I’ll walk you through solving some of them with a detailed explanation.
1. Ammonium Carbonate Problems:
Molar Mass of Ammonium Carbonate (NH₄CO₃):
To calculate the molar mass of ammonium carbonate, sum the atomic masses of its constituent elements (nitrogen, hydrogen, carbon, and oxygen):
- Nitrogen (N): 14.01 g/mol
- Hydrogen (H): 1.008 g/mol (x4)
- Carbon (C): 12.01 g/mol
- Oxygen (O): 16.00 g/mol (x3)
Molar mass of ammonium carbonate:
[
\text{Molar mass of NH₄CO₃} = 14.01 + (4 \times 1.008) + 12.01 + (3 \times 16.00) = 78.06 \, \text{g/mol}
]
Mass Percent of Each Element:
The mass percent is the percentage of each element’s mass relative to the total molar mass:
[
\text{Mass percent of N} = \frac{14.01}{78.06} \times 100 = 17.95\%
]
[
\text{Mass percent of H} = \frac{(4 \times 1.008)}{78.06} \times 100 = 5.17\%
]
[
\text{Mass percent of C} = \frac{12.01}{78.06} \times 100 = 15.37\%
]
[
\text{Mass percent of O} = \frac{(3 \times 16.00)}{78.06} \times 100 = 61.51\%
]
Moles of Oxygen (O) in 9.85 g of Ammonium Carbonate:
First, find moles of ammonium carbonate:
[
\text{Moles of NH₄CO₃} = \frac{9.85 \, \text{g}}{78.06 \, \text{g/mol}} = 0.126 \, \text{mol}
]
Since there are 3 oxygen atoms per formula unit, multiply the moles of ammonium carbonate by 3:
[
\text{Moles of O} = 0.126 \times 3 = 0.378 \, \text{mol}
]
Hydrogen Atoms in 0.546 lb of Ammonium Carbonate:
Convert pounds to grams:
[
0.546 \, \text{lb} \times 453.59 = 247.05 \, \text{g}
]
Now, calculate the moles of ammonium carbonate:
[
\text{Moles of NH₄CO₃} = \frac{247.05}{78.06} = 3.16 \, \text{mol}
]
Hydrogen atoms are 4 atoms per formula unit, so multiply the moles of ammonium carbonate by 4 (atoms of H):
[
\text{Atoms of H} = 3.16 \times 4 \times 6.022 \times 10^{23} = 7.60 \times 10^{24} \, \text{atoms}
]
Grams of Nitrogen in a Mass Containing 1.23 x 10⁴ Carbon Atoms:
Find moles of carbon:
[
\text{Moles of C} = \frac{1.23 \times 10^4}{6.022 \times 10^{23}} = 2.04 \times 10^{-20} \, \text{mol}
]
Since there is one nitrogen atom for each carbon atom, the moles of nitrogen will be the same. Now, convert moles of nitrogen to grams:
[
\text{Grams of N} = 2.04 \times 10^{-20} \times 14.01 = 2.86 \times 10^{-19} \, \text{g}
]
For the other substances and problems on this worksheet, the process remains similar:
- Calculate molar masses.
- Find the moles by converting mass to moles using the molar mass.
- Use stoichiometric ratios to find the atoms or molecules.
- If needed, convert between grams, moles, atoms, or molecules.
If you need more specific details on the other substances (like Sodium Phosphate or Turquoise), let me know, and I can continue solving them for you!
To help illustrate this better, I’ll generate an image summarizing the solution steps with a visual representation of moles and stoichiometry.
Here is an educational diagram illustrating the stoichiometry concepts you need. It shows the relationship between mass, moles, atoms, and molecules, using ammonium carbonate as an example. This visual should help clarify the steps in converting grams to moles and finding the number of atoms and molecules involved in chemical calculations. Let me know if you’d like further explanations or more details on any specific part of the worksheet!
