Characteristic properties are used because the sample size and the shape of the substance does not matter.
Answer:
3.64g
Explanation:
Given parameters:
Mass of NH₃ = 18.1g
Mass of Cu₂O = 90.4g
Unknown:
Limiting reactant = ?
Mass of N₂ formed = ?
Solution:
The reaction equation is given as:
Cu₂O + 2NH₃ → 6Cu + N₂ + 3H₂O
The limiting reactant is the one in short supply in the reaction. Let us find the number of moles of the given species;
Number of moles =
Molar mass of Cu₂O = 2(63.6) + 16 = 143.2g/mol
Molar mass of NH₃ = 14 + 3(1) = 17g/mol
Number of moles of Cu₂O =
= 0.13moles
Number of moles of NH₃ =
= 5.32moles
From this reaction;
1 mole of Cu₂O combines with 2 mole of NH₃
So 0.13moles of Cu₂O will combine with 0.13 x 2 mole of NH₃
= 0.26moles of NH₃
Therefore, Cu₂O is the limiting reactant. Ammonia is in excess;
Mass of N₂;
Mass = number of moles x molar mass
1 mole of Cu₂O will produce 1 mole of N₂
0.13 mole of Cu₂O will produce 0.13 mole of N₂
Mass = 0.13 x (2 x 14) = 3.64g
Answer:
The yeast present contains an enzyme called catalase which catalyses the reaction. More the amount of the catalyst added, faster will be the decomposition of the hydrogen peroxide.
Answer:
a) cu2+ + 1Hg (l) 1Cl- equilibrium cu (s) + Hg2Cl2 (s)
b) 0.068 V.
Explanation:
A) Cu2+ + 2e- euilibrium cu (s)
Hg2Cl2 + 2e- equilibrium 2Hg (l) + 1cl-
Cell Reaction: cu2+ + 1Hg (l) 1Cl- equilibrium cu (s) + Hg2Cl2 (s)
B) To calculate the cell voltage
E = E_o Cu2+/Cu - (0.05916 V / 2) log 1/Cu2+
putting values we get
= 0.339V + (90.05916V/2)log(0.100) = 0.309V
E_cell = E Cu2+/Cu - E SCE = 0.309 V - 0.241 V = 0.068V.