Answer:
The higher the excitation state, the more energy the electron contains. When an electron absorbs energy, it jumps to a higher orbital. ... An electron in an excited state can release energy and 'fall' to a lower state.
Facts about Pumice:
The lightest rock on earth.
Formed in Molten Lava.
Most of the earths crust is made from rocks such as Pumice (Igneous Rocks).
Contains many minerals that help plants to grow.
Facts about Sandstone:
It can form on land or in the sea.
It has been used as far back as prehistoric times to make house ware items and shelter contruction.
They can take thousands of years to form.
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Answer:
10.8 g
Explanation:
<em>A chemist adds 480.0 mL of a 0.169 mol/L aluminum chloride solution to a reaction flask. Calculate the mass in grams of aluminum chloride the chemist has added to the flask. Round your answer to 3 significant digits.</em>
Step 1: Given data
- Volume of the solution: 480.0 mL
- Concentration of the aluminum chloride solution: 0.169 mol/L
Step 2: Calculate the moles of aluminum chloride in the solution
We will multiply the volume of the solution by the molarity.
0.4800 L × 0.169 mol/L = 0.0811 mol
Step 3: Calculate the mass corresponding to 0.0811 moles of AlCl₃
The molar mass of AlCl₃ is 133.34 g/mol.
0.0811 mol × 133.34 g/mol = 10.8 g
Answer:
See explanation
Explanation:
If heat is given out in a reaction, then that reaction is exothermic. If heat is absorbed in a reaction, then that reaction is endothermic.
Hence, if heat is given out, the reaction is exothermic. The heat given out does work on the surrounding thus the laws of conservation of energy are obeyed.
Answer:
T = 215.33 °C
Explanation:
The activation energy is given by the Arrhenius equation:
<u>Where:</u>
k: is the rate constant
A: is the frequency factor
Ea: is the activation energy
R: is the gas constant = 8.314 J/(K*mol)
T: is the temperature
We have for the uncatalyzed reaction:
Ea₁ = 70 kJ/mol
And for the catalyzed reaction:
Ea₂ = 42 kJ/mol
T₂ = 20 °C = 293 K
The frequency factor A is constant and the initial concentrations are the same.
Since the rate of the uncatalyzed reaction (k₁) is equal to the rate of the catalyzed reaction (k₂), we have:
(1)
By solving equation (1) for T₁ we have:
Therefore, we need to heat the solution at 215.33 °C so that the rate of the uncatalyzed reaction is equal to the rate of the catalyzed reaction.
I hope it helps you!
