Answer:
This question appears incomplete
Explanation:
This question appears incomplete because of the absence of options. However, hydrogen is placed in group 1 because it has just one electron in it's outermost shell (which happens to be the only shell it has) just like every other group 1A/group 1 element. While helium is placed in group 8A/group 18 because it has a completely filled outermost shell (which is also the only shell it has) just like every other element in group 8A/group 18.
2C2H5OH + 2Na ---- 2C2H5ONa + H2
Answer:
1.818x10²³ particles
Explanation:
Add the two atomic masses given to get 74.55 g.
Divide the number of grams given by the molar mass of KCl:
22.5g ÷ 74.55 = 0.302 mol
Multiply the moles by 6.022×10²³ particles
Answer:
- The last option: <u><em>Decrease the volume to increase pressure and to increase concentration.</em></u>
Explanation:
You can support your choice on basis of the collision theory.
According to the collision theory, the chemical reactions happen when the molecules collide with each other, in the correct orientation and with enough kinetic energy to overcome the activation energy.
As consequence, the larger the number of collisions the larger the rate of a reaction.
In the case of a reaction that involves gases, decreasing the volume, will increase the pressure and the concentration (volume is inversely related to both the pressure and the concentration) causing the molecules to be closer to each other and to collide with higher frequency, this is you will expect more collisions, and so an increase on the rate of the reaction. That is expressed by the last choice: decrease the volumen to increase pressure and to increase concentration.
