Answer:
5.37 × 10⁻⁴ mol/L
Explanation:
<em>A chemist makes 660. mL of magnesium fluoride working solution by adding distilled water to 230. mL of a 0.00154 mol/L stock solution of magnesium fluoride in water. Calculate the concentration of the chemist's working solution. Round your answer to 3 significant digits.</em>
Step 1: Given data
- Initial concentration (C₁): 0.00154 mol/L
- Initial volume (V₁): 230. mL
- Final concentration (C₂): ?
- Final volume (V₂): 660. mL
Step 2: Calculate the concentration of the final solution
We want to prepare a dilute solution from a concentrated one. We can calculate the concentration of the final solution using the dilution rule.
C₁ × V₁ = C₂ × V₂
C₂ = C₁ × V₁ / V₂
C₂ = 0.00154 mol/L × 230. mL / 660. mL = 5.37 × 10⁻⁴ mol/L
Answer: Each pair of shared electrons is a covalent bond which can be represented by a dash.
Explanation:
In a Lewis dot structure, the central atom can share electrons through bonds with the surrounding atoms, and this can look like a dash between the atoms.
<span>Chemical reaction: CH</span>₃COO⁻(aq) + H⁺(aq) ⇄ CH₃COOH(aq).
H⁺ is from HNO₃: HNO₃ → H⁺ + NO₃⁻.
<span>A buffer can
be defined as a substance that prevents the pH of a solution from changing by
either releasing or absorbing H</span>⁺ in a
solution.
Buffer is a solution
that can resist pH change upon the addition of an acidic or basic components
and it is able to neutralize small amounts of added acid or base, pH of
the solution is relatively stable.
The enthalpy change is negative.
The other statements are false because:
Can take place without a catalyst
Energy is given out to the surroundings.
Kinetic energy of products is higher.
