When 2.5g of ammonium dichromate is heated, the mass of nitrogen and water vapor released is 1.0g. What is the final mass of the solid product?
Cr203=1.5 grams
To find the final mass of the solid product, we need to consider the conservation of mass. The mass of the reactants should be equal to the mass of the products.
Given:
Mass of ammonium dichromate = 2.5g
Mass of nitrogen and water vapor released = 1.0g
In this reaction, ammonium dichromate decomposes into nitrogen gas (N₂) and water vapor (H₂O).
The balanced equation for the reaction is:
(NH₄)₂Cr₂O₇ → N₂ + 4H₂O + Cr₂O₃
From the balanced equation, we can see that 1 mole of ammonium dichromate will produce 1 mole of nitrogen gas, 4 moles of water, and some chromium(III) oxide.
To find the number of moles of nitrogen gas produced, we need to convert the mass of nitrogen to moles using its molar mass.
The molar mass of nitrogen (N₂) is approximately 28 g/mol.
Number of moles of nitrogen = mass of nitrogen / molar mass of nitrogen
Number of moles of nitrogen = 1.0g / 28 g/mol ≈ 0.036 mol
Since 1 mole of ammonium dichromate produces 1 mole of nitrogen gas, the number of moles of ammonium dichromate decomposed is also approximately 0.036 mol.
The molar mass of ammonium dichromate ((NH₄)₂Cr₂O₇) is approximately 252 g/mol.
Mass of ammonium dichromate decomposed = number of moles of ammonium dichromate × molar mass of ammonium dichromate
Mass of ammonium dichromate decomposed = 0.036 mol × 252 g/mol ≈ 9.072 g
The final mass of the solid product can be calculated by subtracting the mass of ammonium dichromate decomposed from the initial mass of ammonium dichromate.
Final mass of solid product = Initial mass of ammonium dichromate - Mass of ammonium dichromate decomposed
Final mass of solid product = 2.5 g - 9.072 g ≈ -6.572 g
However, the calculated final mass of the solid product is negative, which doesn't make physical sense. This indicates that something went wrong in the calculations or that the given information is incorrect. Please double-check the values given or the calculations performed.
To find the final mass of the solid product, we need to calculate how much mass was lost due to the release of nitrogen and water vapor.
Given:
Mass of ammonium dichromate = 2.5g
Mass of released nitrogen and water vapor = 1.0g
To calculate the mass loss, we subtract the mass of the released nitrogen and water vapor from the initial mass of ammonium dichromate:
Mass loss = Mass of ammonium dichromate - Mass of released nitrogen and water vapor
Mass loss = 2.5g - 1.0g
Mass loss = 1.5g
Therefore, the mass loss due to the release of nitrogen and water vapor is 1.5g.
To find the final mass of the solid product, we subtract the mass loss from the initial mass of ammonium dichromate:
Final mass of solid product = Mass of ammonium dichromate - Mass loss
Final mass of solid product = 2.5g - 1.5g
Final mass of solid product = 1.0g
Therefore, the final mass of the solid product is 1.0g.
(NH4)2Cr2O7 → Cr2O3 + N2 + 4H2O
.....2.5...................x........[1.0g]
The Law of conservation of mass tells you that you don't lose anything.
2.5 = mass Cr2O3 + 1.0
mass Cr2O3 = ?