Answer:
7,94 minutes
Explanation:
If the descomposition of HBr(gr) into elemental species have a rate constant, then this reaction belongs to a zero-order reaction kinetics, where the r<em>eaction rate does not depend on the concentration of the reactants. </em>
For the zero-order reactions, concentration-time equation can be written as follows:
[A] = - Kt + [Ao]
where:
- [A]: concentration of the reactant A at the <em>t </em>time,
- [A]o: initial concentration of the reactant A,
- K: rate constant,
- t: elapsed time of the reaction
<u>To solve the problem, we just replace our data in the concentration-time equation, and we clear the value of t.</u>
Data:
K = 4.2 ×10−3atm/s,
[A]o=[HBr]o= 2 atm,
[A]=[HBr]=0 atm (all HBr(g) is gone)
<em>We clear the incognita :</em>
[A] = - Kt + [Ao]............. Kt = [Ao] - [A]
t = ([Ao] - [A])/K
<em>We replace the numerical values:</em>
t = (2 atm - 0 atm)/4.2 ×10−3atm/s = 476,19 s = 7,94 minutes
So, we need 7,94 minutes to achieve complete conversion into elements ([HBr]=0).
Just choose 3
1) Lakes can form in hollows left by meteorite impacts (e.g. Clearwater Lakes, Quebec, Canada).
2) Lakes can form in the craters formed by volcanoes (e.g. Crater Lake, Oragon)
3) Lakes can form when a river is damed by a natural rock fall or man (e.g. Lake Mede)
4) Lakes can form where glaciers have scooped out the rock from the floor of a valley (e.g. Lake Geneva)
5) Lakes can form where block faulting lowers the land (e.g. lake Baikal)
6) lakes can form in natural depressions in the land (e.g. Lake Victoria)
Answer:
Fe
Explanation:
The cell potential is:
ΔE°cell = E°red(red) - E°red(oxid)
Where, E°red(red) is the reduction potential of the substance that is reducing, and E°red(oxid) is the reduction potential of the substance that is oxidizing. For the reaction be spontaneous and happen, ΔE°cell > 0.
The reduction takes place in the cathode, which is the negative pole, and the oxidation in the anode, which is the positive pole. So, the electrons flow from the positive pole to the negative pole (anode to cathode).
Then, if the voltmeter measured a negative potential, it means that is was attached incorrectly. So, the anode is Fe.
Answer:
<em>The correct option is C) Very low</em>
Explanation:
In physics, resistance can be described as the opposition to the flow of current or the flow of electrons. Conductors are known to be materials which can conduct electricity. Hence, conductivity and resistance are opposite to each other. Good conductors will have very little or no resistance and will have enhanced conductivity. On the contrary, insulators are materials which will have more resistance and they cannot conduct electricity as efficiently.
