Answer: Option (a) is the correct answer.
Explanation:
It is known that elements which have completely filled octet when they are present in neutral state then they do not need to gain or lose an electron. Hence, the element becomes unreactive in nature.
For example, neon is a noble gas whose atomic number is 10 and its electronic distribution is 2, 8. As they have completely filled orbitals so they do not react with other elements.
As a result, they are rarely found in combination with other elements.
Thus, we can conclude that the Group 8A(18) elements are unreactive and are rarely found in combination with other elements.
Answer is: molarity of solution is 0,5 mol/dm³.
m(NaOH) = 10,0 g.
V(NaOH) = 500 ml = 0,5 dm³.
c(NaOH) = ?
n(NaOH) = m(NaOH) ÷ M(NaOH).
n(NaOH) = 10,0 g ÷ 40 g/mol.
n(NaOH) = 0,25 mol.
c(NaOH) = n(NaOH) ÷ V(NaOH).
c(NaOH) = 0,25 mol ÷ 0,5 dm³.
c(NaOH) = 0,5 mol/dm³.
Kg=24,590550 g=24590,550 mg=24590550
Answer:
3.34×10³⁰ molecules of C₉H₈O₄
Explanation:
Let's determine the molar mass of aspirin:
C₉H₈O₄ → 12 g/mol . 9 + 1g/mol . 8 + 16g/mol . 4 = 180 g/mol
Let's convert the mass from g to mg → 180 g . 1000 mg/1g = 180000 mg
= 1.8×10⁵ mg
Now, we make a rule of three:
In 1.8×10⁵ mg of aspirin (1 mol) we have 6.02×10²³ molecules
In 100 mg of aspirin, we may have ( 100 . 6.02×10³) / 1.8×10⁵ = 3.34×10³⁰ molecules
Because they used to be alive
