Answer:
11.2 M
Explanation:
Given data:
Number of moles = 6.7 mol
Volume of solution = 0.6 L
Concentration /Molarity = ?
Solution:
Molarity:
It is number of moles of solute in to per kg or litters of solution. It can be calculated by the following formula.
Molarity = number of moles / Volume in L
Now we will put the values in formula.
Molarity = 6.7 mol / 0.6 L
Molarity = 11.2 mol/L
Molarity = 11.2 M
Answer:
Chemical symbol
This is used to identify an element without having to write the full name and as such is a designation for the element. It is used in chemical reactions and is usually either one or two letters. Some symbols are, Iron - Fe, Hydrogen - H and Oxygen - O.
Valency
This refers to the capacity of an element to combine with another to form a compound. It is measured by the number of electrons that an atom of an element gains, looses or shares when a chemical reaction involving it takes place.
3Si + 2N2 --> Si3N4 (as given)
n(Si) = m/MM = 38.25/28.085 = 1.3619 mol
n(N2) = 14.33/2*14.007 = 0.5115 mol
Therefore, N2 is limiting and Si is in excess
The molar ratio of 2N2:Si3N4 is 2:1
So, 0.0575 mol of silicon nitride is formed (dividing 0.5115 by 2)
m of silicon nitride= n*mm = 0.0575*140.283 = 8.06627... g
= 8.066g (4 significant figures)
(hopefully it is right, but double check in case i did something wrong) :)
Sodium Na is a metal that belong to the alkali metal with low density and soft
