Write a balanced chemical equation for the aqueous reaction between potassium hydroxide and hydrobromic acid. Include physical states. Question options: KOH (s) + HBr (g) ® H2O (l) + KBr (aq) KOH (s) + HBr (g) ® H2O (l) + KBr (s) KOH (s) + HBr (aq) ® H2O (l) + KBr (s) KOH (aq) + HBr (aq) ® H2O (l) + KBr (aq)
The Correct Answer and Explanation is:
The correct balanced chemical equation for the reaction between potassium hydroxide (KOH) and hydrobromic acid (HBr) in aqueous solution is:
KOH (aq) + HBr (aq) → H2O (l) + KBr (aq)
Explanation:
Reaction Type: This is an acid-base neutralization reaction. Potassium hydroxide (KOH), a strong base, reacts with hydrobromic acid (HBr), a strong acid, to form water (H2O) and potassium bromide (KBr), which is an ionic salt.
Physical States:
KOH (aq): Potassium hydroxide is commonly dissolved in water, so it’s in aqueous form (aq).
HBr (aq): Hydrobromic acid is also an aqueous solution when it is dissolved in water.
H2O (l): Water is the product of the neutralization reaction and is in the liquid state.
KBr (aq): Potassium bromide is an ionic compound that dissociates into K+ and Br- ions in water, making it aqueous (aq).
Why KOH (aq) and HBr (aq)?
For the reaction to occur in aqueous form, both KOH and HBr must be in solution (aq). If either of these compounds is in a solid or gaseous state, the reaction would not take place as efficiently or in the same manner.
KOH (s) and HBr (g) are not typical forms for a neutralization reaction because potassium hydroxide is usually dissolved in water for easy dissociation, and hydrobromic acid is most often encountered as an aqueous solution rather than a gas.
Balanced Equation:
There is no need for coefficients to balance the equation in this case, as the number of atoms on both sides of the equation is already equal.
The products of the reaction are water (H2O) and potassium bromide (KBr), and both are formed in the correct proportions from the reactants.
Thus, the balanced equation is:
KOH (aq) + HBr (aq) → H2O (l) + KBr (aq)
