Question

question 5 10 pts which one of the following aqueous solutions has the ph lower than 7? 0.01 m h₂so₄ 20% sucrose (table sugar, c₁₂h₂₂o₁₁) 0.01 m koh 0.01 m kcl question 6 10 pts which two species are a conjugate acid/base pair? h₂co₃/hco₃⁻ hcl/hbr koh/naoh h₃po₄/po₄³⁻

Explanation:

Step1: Recall pH - acid - base concepts

Acidic solutions have pH < 7, basic solutions have pH > 7 and neutral solutions have pH = 7.

Step2: Analyze each option in Question 5

• $H_2SO_4$ is a strong acid. In $0.01\ M\ H_2SO_4$, it dissociates to produce $H^+$ ions, so the solution is acidic (pH < 7).
• Sucrose ($C_{12}H_{22}O_{11}$) is a non - electrolyte and its solution is neutral (pH = 7).
• $KOH$ is a strong base. In $0.01\ M\ KOH$, it dissociates to produce $OH^-$ ions, so the solution is basic (pH>7).
• $KCl$ is a salt of a strong acid ($HCl$) and a strong base ($KOH$), and its solution is neutral (pH = 7).

Step3: Recall conjugate acid - base pair concept

A conjugate acid - base pair differs by a single $H^+$.

Step4: Analyze each option in Question 6

• For $H_2CO_3/HCO_3^-$, $H_2CO_3$ can donate a proton to form $HCO_3^-$, so they are a conjugate acid - base pair.
• $HCl$ and $HBr$ are different acids, not a conjugate acid - base pair.
• $KOH$ and $NaOH$ are bases, not a conjugate acid - base pair.
• $H_3PO_4$ and $PO_4^{3 - }$ differ by three $H^+$ ions, not a single $H^+$, so they are not a conjugate acid - base pair.

Answer:

Question 5: 0.01 M $H_2SO_4$
Question 6: $H_2CO_3/HCO_3^-$