Answer:
<h2>The answer is option D</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>1.20 moles</h3>Hope this helps you
Answer : The pH of the solution is, 1.31
Explanation : Given,
Mass of = 248 mg = 0.248 g (1 mg = 0.001 g)
Volume of solution = 140 mL
Molar mass of = 36.5 g/mole
First we have to calculate the concentration of hydrochloric acid.
Molarity : It is defined as the number of moles of solute present in one liter of volume of solution.
Formula used :
Now put all the given values in this formula, we get:
The concentration of HCl is, 0.0485 M
As we know that, HCl dissociates to give hydrogen ion and chloride ion.
The dissociation reaction is:
Concentration of HCl = Concentration of H⁺ = Concentration of Cl⁻ = 0.0485 M
Now we have to calculate the pH of the solution.
pH : It is defined as the negative logarithm of hydrogen ion concentration.
Mathematically,
Therefore, the pH of the solution is, 1.31