1. what weight in grams of magnesium oxide will produce from burning 96 grams of magnesium?
2. a solution containing 252g of calcium sulfate will produce from 165lbs of phosphate rocks containing 82.5 % pure calcium phosphate treated with sulfuric acid?
3. how many tons of quicklime(calcium oxide)yield out of heating 675 tons of limestone(impure calcium carbonate) containing 95 % pure calcium carbonate?
4. calculate the amt of hydrogen liberated in liter when 260g of zinc treated with sulfuric acid?
To find the answers to these questions, we need to use stoichiometry, which is a way to relate the quantities of reactants and products in a chemical reaction. The key is to use the balanced chemical equations that represent the reactions involved. Let's tackle each question step by step:
1. To determine the mass of magnesium oxide produced from burning magnesium, we start by writing the balanced chemical equation for the reaction:
2Mg + O₂ → 2MgO
From the equation, we see that 2 moles of magnesium react to form 2 moles of magnesium oxide. The molar mass of magnesium is 24.31 grams/mole, and magnesium oxide is 40.30 grams/mole.
First, we calculate the number of moles of magnesium in 96 grams using its molar mass:
96 grams / 24.31 grams/mole = 3.95 moles of magnesium
Using the stoichiometry of balanced equation, 2 moles of magnesium produce 2 moles of magnesium oxide. Therefore, we have:
3.95 moles of magnesium * (2 moles of MgO / 2 moles of Mg) = 3.95 moles of magnesium oxide
Finally, multiply the moles of magnesium oxide by its molar mass to get the weight in grams:
3.95 moles of magnesium oxide * 40.30 grams/mole ≈ 159 grams of magnesium oxide
So, 96 grams of magnesium will produce approximately 159 grams of magnesium oxide.
2. To determine the amount of calcium sulfate solution produced from phosphate rocks, we need to write the balanced chemical equation:
Ca₃(PO₄)₂ + 3H₂SO₄ → 3CaSO₄ + 2H₃PO₄
From the equation, we can see that 1 mole of calcium phosphate reacts with 3 moles of sulfuric acid to form 3 moles of calcium sulfate. The molar mass of calcium sulfate is 136.14 grams/mole.
First, determine the number of moles of calcium sulfate by using the molar mass and the given mass of calcium sulfate:
252 grams / (136.14 grams/mole) = 1.85 moles of calcium sulfate
Use the stoichiometry of the balanced equation to convert the moles of calcium sulfate to moles of calcium phosphate:
1.85 moles of calcium sulfate * (1 mole of Ca₃(PO₄)₂ / 3 moles of CaSO₄) = 0.62 moles of calcium phosphate
Now, calculate the mass of calcium phosphate by multiplying the moles of calcium phosphate by its molar mass:
0.62 moles of calcium phosphate * (310.18 grams/mole) ≈ 192 grams of calcium phosphate
Therefore, from 165 lbs of phosphate rocks containing 82.5% pure calcium phosphate, approximately 192 grams of calcium phosphate will be produced.
3. To determine the amount of quicklime (calcium oxide) yielded from heating limestone (calcium carbonate), we need to write the balanced chemical equation:
CaCO₃ → CaO + CO₂
From the equation, we can see that 1 mole of calcium carbonate reacts to form 1 mole of calcium oxide. The molar mass of calcium oxide is 56.08 grams/mole.
First, determine the number of moles of calcium carbonate using its molar mass and the given mass of limestone:
675 tons * (907.19 kg/ton) * (1,000 g/kg) * (0.95) / (100.09 grams/mole) ≈ 646,304 moles of calcium carbonate
Since the stoichiometry of the balanced equation is 1:1, the number of moles of calcium oxide will be the same:
646,304 moles of calcium oxide
Now, we calculate the mass of calcium oxide by multiplying the moles of calcium oxide by its molar mass:
646,304 moles of calcium oxide * (56.08 grams/mole) ≈ 36,260,890 grams, or approximately 36,261 tons of calcium oxide.
Hence, from heating 675 tons of limestone containing 95% pure calcium carbonate, approximately 36,261 tons of quicklime will be yielded.
4. To determine the amount of hydrogen liberated when treating zinc with sulfuric acid, we first need to write the balanced chemical equation:
Zn + H₂SO₄ → ZnSO₄ + H₂
From the equation, we can see that 1 mole of zinc reacts with 1 mole of sulfuric acid to produce 1 mole of hydrogen. The molar mass of hydrogen is 2.02 grams/mole.
First, calculate the number of moles of zinc using its molar mass and the given mass of zinc:
260 grams / (65.38 grams/mole) ≈ 3.97 moles of zinc
Using the stoichiometry of the balanced equation, the moles of zinc will produce an equal amount of moles of hydrogen:
3.97 moles of hydrogen
Finally, convert the moles of hydrogen to liters using the ideal gas law, assuming standard temperature and pressure (STP):
3.97 moles of hydrogen * (22.4 liters/mole) ≈ 88.93 liters
Therefore, when 260 grams of zinc is treated with sulfuric acid, approximately 88.93 liters of hydrogen will be liberated.