In analytical chemistry, a standard solution<span> is a </span>solution<span> containing a precisely known concentration of an element or a substance. A known weight of solute is dissolved to make a specific volume.</span>
A - its condensation and gas particles have a higher kinetic energy
Answer:
35.8 u
Explanation:
The atomic mass of Cl is the weighted average of the atomic masses of its isotopes.
We multiply the atomic mass of each isotope by a number representing its relative importance (i.e., its percent abundance).
Atomic mass of Cl-35 = 17p + 18n = 17 × 1.007 u + 18 × 1.009 u
= 17.119 u + 18.162 u = 35.28 u
Atomic mass of Cl-37 = 17p + 20n = 17 × 1.007 u + 20 × 1.009 u
= 17.119 u + 20.180 u = 37.30 u
Set up a table for easy calculation.
0.755 × 35.28 u = 26.64 u
0.245 × 37.30 u = 9.138 u
TOTAL = 35.8 u
Note: The actual atomic mass of Cl is 35.45 u.
The calculated value above is incorrect because
(a) the given isotopic percentages are incorrect and
(b) the protons and neutrons have less mass when they are in the nucleus than when they are free. Thus, the calculated masses of Cl-35 and Cl-37 are too high.
Answer:
<h2>7142.86 moles</h2>
Explanation:
To find the number of moles in a substance given it's number of entities we use the formula
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
We have the final answer as
<h3>7142.86 moles</h3>
Hope this helps you
