The answer is "A. a pure substance can be separated by chemical means, while a mixture can be separated by physical means". A pure substance only has one type of substance, whereas a mixture has more than one. A pure substance therefore, can only be separated chemically, because it is not two things mixed together, whereas a mixture can be separated physically because there are multiple substances.
Answer: 6.022x10²³ (Avogadro's Number)
Explanation: The number of particles in 1 mole of a substance is determined by the Avogadro's Number.
Answer:
I think it is covalent bonding...
Explanation:
The bonding is covalent in homonuclear diatomic molecules. Each atom in the molecule has the same electronegativity, which means electrons are shared equally between the two. The electronegativity of the atoms in heteronuclear diatomic molecules varies, and these molecules have polar covalent bonds. A dipole is formed when a molecule interacts with another molecule. (i think it's covalent bonding but i might be wrong)
hope this helps...
Answer:
<u>The deviations are :</u>
- <u>The activation energy which changes with temperature</u>
- <u>The arrhenius constant which depends on the temperature</u>
Explanation:
- There are deviations from the Arrhenius law during the glass transition in all classes of glass-forming matter.
- The Arrhenius law predicts that the motion of the structural units (atoms, molecules, ions, etc.) should slow down at a slower rate through the glass transition than is experimentally observed.
- In other words, the structural units slow down at a faster rate than is predicted by the Arrhenius law.
- <em>This observation is made reasonable assuming that the units must overcome an energy barrier by means of a thermal activation energy. </em>
- The thermal energy must be high enough to allow for translational motion of the units <em>which leads to viscous flow of the material.</em>
- Both the Arrhenius activation energy and the rate constant k are experimentally determined, and represent macroscopic reaction-specific parameters <em>that are not simply related to threshold energies and the success of individual collisions at the molecular level. </em>
- Consider a particular collision (an elementary reaction) between molecules A and B. The collision angle, the relative translational energy, the internal (particularly vibrational) energy will all determine the chance that the collision will produce a product molecule AB.
- Macroscopic measurements of E(activation energy) and k(rate constant ) <em>are the result of many individual collisions with differing collision parameters. </em><em>They are averaged out to a macroscopic quantity.</em>
Answer:
The pH of the solution is 2.56.
Explanation:
Given :
Concentration (c) = 0.40 M
Acid dissociation constant = 
The equilibrium reaction for dissociation of 
(weak acid) is,
initially conc. c 0 0
At eqm. 
Dissociation constant is given as:
By solving the terms, we get value of 
No we have to calculate the concentration of hydronium ion or hydrogen ion.
![[H^+]=c\alpha=0.4\times 0.00686832=0.002747 M](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3Dc%5Calpha%3D0.4%5Ctimes%200.00686832%3D0.002747%20M)
Now we have to calculate the pH.
![pH=-\log [H^+]](https://tex.z-dn.net/?f=pH%3D-%5Clog%20%5BH%5E%2B%5D)
Therefore, the pH of the solution is, 2.56.
