Answer:
Starch is a viable indicator in the titration process because it turns deep dark blue when iodine is present in a solution. When starch is heated in water, decomposition occurs and beta-amylose is produced
Answer:
Benzoic acid is the stronger acid
Explanation:
Weak acids do not dissociate completely in the solution. They exists in equilibrium with their respective ions in the solution.
The extent of dissociation of the acid furnising hydrogen ions can be determined by using dissociation constant of acid (
).
Thus for a weak acid, HA

The
is:
![K_a= \frac{[A^-][H^+]}{[HA]}](https://tex.z-dn.net/?f=K_a%3D%20%5Cfrac%7B%5BA%5E-%5D%5BH%5E%2B%5D%7D%7B%5BHA%5D%7D)
The more the
, the more the acid dissociates, the more the stronger is the acid.
Also,
is defined as the negative logarithm of
.
So, more the
, less is the
and vice versa
All can be summed up as:
The less the value of
, the more the
is and the more the acid dissociates and the more the stronger is the acid.
Given,
of acetic acid = 54.7
of benzoic acid = 54.2
of benzoic acid <
of acetic acid
So, benzoic acid is the stronger acid.
Answer:
0.161moles
Explanation:
Given parameters:
Mass of Fe = 18g
Oxygen gas is in excess
Unknown:
Number of moles of Fe₂O₃ produced = ?
Solution:
To start with, let us write a chemically balanced equation before proceeding to understand the nuances of this problem.
4Fe + 3O₂ → 2Fe₂O₃
In the equation above above, 4 mole of iron combined with 3 moles of oxygen gas to 2 moles of Fe₂O₃.
In solving this problem, we can identify that Fe is the limiting reactant since we have been told oxygen gas is in excess. The suggests that the extent to which the product is formed and the reaction proceeds hinges on the amount of Fe we have.
It is best to work from the given, or known reactant to the unknown
The known in this scenario is the mass of Fe. Let us find the number of moles of this specie;
Number of moles of Fe = 
Molar mass of Fe = 56g/mol
Number of moles =
= 0.32mol
Using this known number of moles of Fe, we can relate it to that of the unknown amount of the product and obtain the number of moles.
4 moles of Fe produced 2 moles of Fe₂O₃
0.32 moles of Fe will produce
= 0.161moles
Valence electrons form bonds to create molecules and compounds because A. they are weaker than the electrons found closer to the nucleus.
A better way of saying it is that the valence electrons are <em>less strongly attracted</em> to the nucleus.
All electrons have the same size, but the <em>orbitals</em> they occupy have different sizes.