Answer:
2Au₂S₃ + 6H₂ → 4Au + 6H₂S
Explanation:
Balancing:
2Au₂S₃ + 6H₂ → 4Au + 6H₂S
Answer:
0.0177 L of nitrogen will be produced
Explanation:
The decomposition reaction of sodium azide will be:
As per the balanced equation two moles of sodium azide will give three moles of nitrogen gas
The molecular weight of sodium azide = 65 g/mol
The mass of sodium azide used = 100 g
The moles of sodium azide used = 
so 1.54 moles of sodium azide will give = 
mol
the volume will be calculated using ideal gas equation
PV=nRT
Where
P = Pressure = 1.00 atm
V = ?
n = moles = 2.31 mol
R = 0.0821 L atm / mol K
T = 25 °C = 298.15 K
Volume = 
We write DE = q+w, where DE is the internal energy change and q and w are heat and work, respectively.
(b)Under what conditions will the quantities q and w be negative numbers?
q is negative when heat flows from the system to the surroundings, and w is negative when the system does work on the surroundings.
As an aside: In applying the first law, do we need to measure the internal energy of a system? Explain.
The absolute internal energy of a system cannot be measured, at least in any practical sense. The internal energy encompasses the kinetic energy of all moving particles in the system, including subatomic particles, as well as the electrostatic potential energies between all these particles. We can measure the change in internal energy (DE) as the result of a chemical or physical change, but we cannot determine the absolute internal energy of either the initial or the final state. The first law allows us to calculate the change in internal energy during a transformation by calculating the heat and work exchanged between the system and its surroundings.
Answer:
Explanation:
a )
1.25 g MgO contains .754 g of Mg .Rest will be O
so oxide = 1.25 - .754 = 0.496 g
ratio of magnesium to oxide = .754/.496 = 1.52
b) 1.25 g of MgO contains .754 g of Mg
534 g of MgO contains .754 x 534 / 1.25 g = 322.11 g
Answer:
5 mol.
Explanation:
Equation of the reaction
2SO2 + 2H2O + O2 --> 2H2SO4
By stoichiometry, 2 moles of SO2 reacted with 2 moles of water and 1 mole of O2 to give 2 mole of sulphuric acid.
Number of moles:
5.0 mol SO2
4.0 mol O2
20.0 mol H2O
Calculating the limiting reagent,
5 mol of SO2 * 1 mol of O2/2 mol of SO2
= 2.5 mol of O2(4 mol of O2 is present)
5 mol of SO2 * 2 mol of H2O/2 mol of SO2
= 5 mol of H2O(20 mol of H2O)
SO2 is the limiting reagent.
Therefore, number of moles of H2SO4 = 5 mol of SO2 * 2 mol of H2SO4/2 mol of SO2
= 5 mol of H2SO4.
