<span>A device that generates an intense beam of coherent monochromatic light (or other electromagnetic radiation) by stimulated emission of photons from excited atoms or molecules. Lasers are used in drilling and cutting, alignment and guidance, and in surgery; the optical properties are exploited in holography, reading bar codes, and in recording and playing compact discs.</span>
Answer:
1) Increasing the pressure A) Shift to the left
2) Removing hydrogen gas B) Shift to the right
3) Adding a catalyst C) No effect
Explanation:
- <em>Le Châtelier's principle states that when there is an dynamic equilibrium, and this equilibrium is disturbed by an external factor, the equilibrium will be shifted in the direction that can cancel the effect of the external factor to reattain the equilibrium.</em>
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<u><em>1) Decreasing the pressure:</em></u>
- When there is an increase in pressure, the equilibrium will shift towards the side with fewer moles of gas of the reaction. And when there is a decrease in pressure, the equilibrium will shift towards the side with more moles of gas of the reaction.
- The reactants side (left) has 4.0 moles of gases and the products side (right) has 2.0 moles of gases.
- So, decreasing the pressure will shift the reaction to the side with more moles of gas (left side).
<u><em>so, the right match is: A) Shift to the left.</em></u>
<em><u>2) Adding hydrogen gas:</u></em>
- Adding hydrogen gas will increase the concentration of the reactants side, so the reaction will be shifted to the right side to suppress the increase in the concentration of hydrogen gas by addition.
<u><em>so, the right match is: B) Shift to the right.</em></u>
<u><em></em></u>
<u><em>3) Adding a catalyst:</em></u>
- Catalyst increases the rate of the reaction without affecting the equilibrium position.
- Catalyst increases the rate via lowering the activation energy of the reaction.
- This can occur via passing the reaction in alternative pathway (changing the mechanism).
- The activation energy is the difference in potential energies between the reactants and transition state (for the forward reaction) and it is the difference in potential energies between the products and transition state (for the reverse reaction).
- in the presence of a catalyst, the activation energy is lowered by lowering the energy of the transition state, which is the rate-determining step, catalysts reduce the required energy of activation to allow a reaction to proceed and, in the case of a reversible reaction, reach equilibrium more rapidly.
- with adding a catalyst, both the forward and reverse reaction rates will speed up equally, which allowing the system to reach equilibrium faster.
<u><em>so, the right match is: B) No effect.</em></u>
<u><em></em></u>
Answer:
- <em>2NaCl → 2Na + Cl₂, ΔH = 822 kJ </em>
Explanation:
The chemical <em>equation</em> for the <em>formation of NaCl</em> is:
- Na + (1/2) Cl₂ → NaCl , ΔH = - 411 kJ
That equation means that 1 mole of NaCl is formed by the reaction of 1 mole of Na and 1/2 mole of Cl₂, with a release of energy of 411 kJ.
The <em>decomposition</em> of <em>NaCl</em> is the inverse of the <em>formation</em> reaction; thus, you swift products and reactants and inverse the sign of the <em>change in enthalpy:</em>
- NaCl → Na + 1/2 Cl₂, ΔH = 411 kJ
Since you want the decomposition of 2 moles you multiply the equation and the ΔH by 2:
- 2NaCl → 2Na + Cl₂, ΔH = 822 kJ ← answer
Answer:
biosphere and lithosphere
Explanation:
The biosphere is described as the zone of life on Earth. It is a sum of all ecosystems. The biosphere is composed of living organisms and non-living factors.
The lithosphere is the outer part of the Earth such that this part is rocky. The lithosphere is made up of the brittle crust.
In general, chemicals enter Ecosystems through the biosphere and lithosphere.
Answer: 2.16 moles Al(CN)3
Explanation: To find the number of moles of Al( CN)3 we will use stoichiometry which is the relationship of mole with molar mass.
227 g Al(CN)3 x 1 mole Al(CN)3 / 105 g Al(CN)3
= 2.16 moles Al(CN)3
Cancel out the unit of grams Al(CN)3 and the remaining unit is in moles Al(CN)3.
