Answer:
The water is universal solvent because it is a polar molecule.This have hydrogen bonding in which hydrogen molecule have positive charge and oxygen molecule have negative charge because electro negativity of oxygen molecule is higher than hydrogen molecule that is why it pull the hydrogen molecule and formed a polar molecule.That is why is also known as universal solvent.
Answer:
A latching relay
Explanation:
A latching relay is a subtype of electromechanical or electromagnet switch. It is a type of relay that maintains its position even after the power is removed. The reason why its used is because they allow a control of circuit by simply providing a single pulse to the relay control circuit.
Mass of Oxygen : 18.8 g
<h3>Further explanation</h3>
Reaction(balanced) :
4Fe + 3O₂ → 2Fe₂O₃
mass Fe = 43.7 g
mol Fe(MW= 55,845 g/mol) :

mol O₂ : mol Fe = 3 : 4, so mol O₂ :

Mass O₂(MW=32 g/mol) :

Or simply you can Conservation of mass, where the masses before and after the reaction are the same
<em>mass reactants=mass products</em>
mass iron+mass oxygen=mass iron (III) oxide
43.7 g + mass oxygen=62.5 g
mass oxygen = 62.5 - 43.7 = 18.8 g
Complete question
The complete question is shown on the first uploaded image
Answer:
The value is 
Explanation:
From the question we are told that
The mass of NaOH is 
In the question DI (stands for de-ionized water )
So the number of moles of NaOH present in the given mass is
Here Z is the molar mass of NaOH with value
So
Given that the volume of the flask is V = 1 L then we can evaluated the concentration as

=> 
=>