Answer:
....,................................
Explanation:
1= A
2=D
3=C
4=C
<span> mass of glucose = 0.055 *165 = 9.075 g
vol of methyl alc = 0.185 * 1.87 = 0.346 L = 346 ml
% NaCl ( m/v ) = mass NaCl * 100/ vol of soln
or Vol of Soln = mass NaCl / % NaCl (m/v)
= 32.1 * 100 / 6 = 535 ml the total vol of soln</span>
false,
sodium has a vigorous reaction with water.
This can be observed by putting a piece of sodium in water,
it moves swiftly across the surface of water and reacts violently.
Answer:
<span>The mole concept is important in chemistry because, "</span>Atoms and molecules are very small and the mole concept allows us to count atoms and molecules by weighing macroscopic amounts of material".
Explanation:
To understand this question lets take an example of Hydrogen atom. Let suppose you need to react Hydrogen with Oxygen. You need exactly Two Hydrogen atoms and one Oxygen atom to form one water molecule.
The mass of 1 hydrogen atom is 1.76 × 10⁻²⁴ grams. How will you count the Hydrogen atoms??? How can you measure exactly for 1 Million Hydrogen Atoms???
Answer to these questions and Calculations lies in Mole. It is found that 1 Mole of Hydrogen weights exactly 1.008 gram and contains 6.022 × 10²³ atoms. Now, having this reference in hand you can calculate for any number of Hydrogen atoms.
Result:
So the Mole helps us to zoom a microscopic level to a macroscopic level. :)
