Answer: The molarity of the initial concentrated solution is 0.450 M
Explanation:
According to the dilution law,
where,
= Molarity of concentrated KOH solution = ?
= volume of concentrated KOH solution = 175 ml
= concentration of diluted KOH solution= 0.315 M
= volume of diluted KOH solution= 250 ml
Putting in the values, we get:
Thus the molarity of the initial concentrated solution is 0.450 M
Periodic table is the representation of elements in an order
The history of periodic table can be summarized as
a) 1829 : Johann Dobereiner proposed the triad rule. According to him we can classify the elements in a triad where the atomic mass of middle element is average of atomic mass of the near by two atoms.
For example : Li, Na and K is a triad. Where atomic mass of Na is average of atomic mass of K
atomic mass of Na = 7+ 39 / 2 = 23
However, with the further discovery of elements the law was rejected.
b) 1864 : John Newland proposed the law of octave. According to him we can arrange the elements in a set of seven elements where the property of second set of seven elements will resemble the properties of first of seven elements or property will be repeated after seven elements. This was also rejected due to its limited applicability.
c) Meyer : He arranged some 28 elements into six different families based on their atomic masses. The members of each familiy shared some common properties.
d) 1869 : Mendleev : He actually developed a periodic table based on atomic mass of elements. He arranged the elements into groups and periods. He even left space for some undiscovered elements, which were later on discovered.
e) 1916 : Henry Moseley : He finally arranged elements based on their atomic number based on X-ray studies. He proposed the modern periodic law that the periodic properties of elements are due to atomic number of elements.
Oxygen is the most common element which Sulfur makes covakent bonds with as in SO3 or H2SO4
Do you need help with all 3 questions or just the one that’s unanswered?
Conduction should be the correct answer.
