Answer:
Adding Catalyst can Speed up a Chemical reaction
Answer: There are
atoms present in 0.500 mol of
.
Explanation:
According to the mole concept, there are
atoms present in 1 mole of a substance.
In a molecule of
there is only one carbon atom present. Therefore, number of carbon atoms present in 0.500 mol of
are as follows.

Thus, we can conclude that there are
atoms present in 0.500 mol of
.
Answer:
Non metals join to form covalent bond.
Explanation:
Covalent bond:
It is formed by the sharing of electron pair between bonded atoms.
The atom with larger electronegativity attract the electron pair more towards it self and becomes partial negative while the other atom becomes partial positive.
For example:
In water the electronegativity of oxygen is 3.44 and hydrogen is 2.2. That's why electron pair attracted more towards oxygen, thus oxygen becomes partial negative and hydrogen becomes partial positive.
Both atoms bonded through covalent bond.
In Cl₂ both chlorine atoms are bonded through the covalent bond.
Answer:
a)
b)
Explanation:
a) The reaction:

The free-energy expression:

![E=E_{red}-E_{ox]](https://tex.z-dn.net/?f=E%3DE_%7Bred%7D-E_%7Box%5D)
The element wich is reduced is the Fe and the one that oxidates is the Mg:

The electrons transfered (n) in this reaction are 2, so:


b) If you have values of enthalpy and enthropy you can calculate the free-energy by:

with T in Kelvin


A, B, C, and D, because they are changing from a solid to a liquid, liquid to solid, and solid to gas. Phase changes are when a solid, liquid, or gas, turns into a solid, liquid, or gas. Ex. Ice melting is a solid changing into a liquid. Hope this helps!