Answer:
162g
Explanation:
We'll begin by writing the balanced equation for the reaction. This is given below:
2C2H6 + 7O2 —> 4CO2 + 6H2O
Next, we shall determine the number of mole of water, H2O produced by the reaction of 3 moles of C2H6.
This can be obtained as follow:
From the balanced equation above,
2 moles of C2H6 reacted to produce 6 moles of H2O.
Therefore, 3 moles of C2H6 will react to produce = (3 x 6)/2 = 9 moles of H2O.
Therefore, 9 moles of H2O is produced from the reaction.
Finally, we shall convert 9 moles of H2O to grams.
This can be done as shown below:
Molar mass of H2O = (2x1) + 16 = 18g/mol
Mole of H2O = 9 moles
Mass of H2O =..?
Mole = mass / molar mass
9 = mass of H2O /18
Cross multiply
Mass of H2O = 9 x 18
Mass of H2O = 162g
Therefore, 162g of H2O were produced from 3 moles of C2H6.
248.72 g/mol
CuSO4 has a molar mass of 159.62. H2O has a molar mass of 18.02, which is multiplied by 5 to reflect the 5 H2O molecules.
159.62+5(18.02)=249.72 g/mol
The answer is the first option (a)
Answer:
The temperature must be changed to 4 times of the initial temperature so as to keep the pressure and the volume the same.
Explanation:
Pressure in the container is P and volume is V.
Temperature of the helium gas molecules =
Molecules helium gas = x
Moles of helium has = 
PV = nRT (Ideal gas equation)
...[1]
After removal of helium gas only a fourth of the gas molecules remains and pressure in the container and volume should remain same.
Molecules of helium left after removal = 
Moles of helium has left after removal = 
...[2]
The temperature must be changed to 4 times of the initial temperature so as to keep the pressure and the volume the same.
Answer:
The standard change in free energy for the reaction = - 437.5 kj/mole
Explanation:
The standard change in free energy for the reaction:
4 KClO₃ (s) → 3 KClO₄(s) + KCl(s)
Given that ΔGf(KClO3(s)) = -290.9 kJ/mol;
ΔGf(KClO4(s)) = -300.4 kJ/mol;
ΔGf(KCl(s)) = -409 kJ/mol
According to Hess's law
ΔGr (Free energy change of reaction)= ∑(Product free energy - reactant free energy)
⇒ ΔGr⁰ = {3 x (-300.4) + (-409)} - {3 x (- 290.9)}
= - 901.2 - 409 + 872.7
= - 437.5 kj/mole
