Answer:
#Molecules XeF₆ = 2.75 x 10²³ molecules XeF₆.
Explanation:
Given … Excess Xe + 12.9L F₂ @298K & 2.6Atm => ? molecules XeF₆
1. Convert 12.9L 298K & 2.6Atm to STP conditions so 22.4L/mole can be used to determine moles of F₂ used.
=> V(F₂ @ STP) = 12.6L(273K/298K)(2.6Atm/1.0Atm) = 30.7L F₂ @ STP
2. Calculate moles of F₂ used
=> moles F₂ = 30.7L/22.4L/mole = 1.372 mole F₂ used
3. Calculate moles of XeF₆ produced from reaction ratios …
Xe + 3F₂ => XeF₆ => moles of XeF₆ = ⅓(moles F₂) = ⅓(1.372) moles XeF₆ = 0.4572 mole XeF₆
4. Calculate number molecules XeF₆ by multiplying by Avogadro’s Number (6.02 x 10²³ molecules/mole)
=> #Molecules XeF₆ = 0.4572mole(6.02 x 10²³ molecules/mole)
= 2.75 x 10²³ molecules XeF₆.
Answer:
The equilibrium will be shifted to lift with the formation of a brown gelatinous precipitate of Fe(OH)₃.
Explanation:
- Le Chatelier's principle states that <em>"when any system at equilibrium for is subjected to change in concentration, temperature, volume, or pressure, then the system readjusts itself to counteract the effect of the applied change and a new equilibrium is established that is different from the old equilibrium"</em>.
- The addition of NaOH will result in the formation of Fe(OH)₃ precipitate which has a brown gelatinous precipitate.
- The formation of this precipitate cause removal and decrease of Fe³⁺ ions.
- According to Le Chatelier's principle, the system will be shifted to lift to increase Fe³⁺ concentration and reduce the stress of Fe³⁺ removal and readjust the equilibrium again. So, the [Fe(SCN)²⁺] decreases.
- Increasing [Fe³⁺] will produce a yellow color solution that contains a brown gelatinous precipitate of Fe(OH)₃.
Energy can be conserved by efficient energy use.
Answer: Option A
<u>Explanation:</u>
Energy can be transferred from one form to another, but it cannot be destroyed or created. So it can be conserved if efficiently used. Thus efficient usage of energy lead to conservation of energy. Due to conservation of energy, the forces can be renewable and non-renewable.
So, we should know how the input energy can be completely converted to another form of energy leading to efficient usage of energy without any loss. As if there is no loss, input energy will be equal to output energy leading to 100% efficiency.
HBr reacts with LiOH and forms LiBr and H₂O as the products. The balanced reaction is
LiOH(aq) + HBr(aq) → LiBr(aq) + H₂O(l)
Molarity (M) = moles of solute (mol) / volume of the solution (L)
Molarity of LiOH = 0.205 M
Volume of LiOH = 29.15 mL = 29.15 x 10⁻³ L
Hence,
moles of LiOH = molarity x volume of the solution
= 0.205 M x 29.15 x 10⁻³ L
= 5.97575 x 10⁻³ mol
The stoichiometric ratio between LiOH and HBr is 1 : 1.
Hence,
moles of HBr in 25.0 mL = moles of LiOH added
= 5.97575 x 10⁻³ mol
Hence, molarity of HBr = 5.97575 x 10⁻³ mol / 25.00 x 10⁻³ L
= 0.23903 M
≈ 0.239 M
Hence, the molarity of the HBr is 0.239 M.
