Q: What is the pH of a $10^{-3} \text{ M } HCl$ solution at $298 \text{ K}$?

$HCl$ is a strong acid, so $H^+ = 10^{-3} \text{ M}$. $pH = -\logH^+ = -\log(10^{-3}) = 3$.

Question 1

At chemical equilibrium, which of the following statements is correct regarding the rate of forward reaction ($rf$) and backward reaction ($rb$)?

Accepted Answer

At chemical equilibrium, the rate of forward reaction becomes equal to the rate of backward reaction ($rf = rb$), making the equilibrium dynamic in nature.

Question 2

What is the correct mathematical relationship between $Kp$ and $Kc$ for a gaseous reaction?

Accepted Answer

The relationship between $Kp$ and $Kc$ is given by $Kp = Kc(RT)^{\Delta ng}$, where $\Delta ng$ is the change in the number of moles of gaseous products and reactants.

Question 3

According to the Lewis concept, an acid is defined as a substance that:

Accepted Answer

According to Lewis theory, an acid is a species that accepts a pair of electrons, whereas a base is an electron pair donor.

Question 4

What is the pH of a $10^{-3} 	ext{ M } HCl$ solution at $298 	ext{ K}$?

Accepted Answer

$HCl$ is a strong acid, so $H^+ = 10^{-3} 	ext{ M}$. $pH = -\logH^+ = -\log(10^{-3}) = 3$.

Question 5

Which of the following mixtures forms an acidic buffer solution?

Accepted Answer

An acidic buffer solution consists of a mixture of a weak acid and its salt with a strong base, e.g., $CH3COOH + CH3COONa$.

Equilibrium