12 Chem MSHS Indicators

What is the primary characteristic of pH indicators?

• They are strong acids
• They change color at different pH
• They are colorless in all solutions
• They are inert substances

What is the main characteristic of indicators in solution?

• They are strong acids
• They are strong bases
• They undergo reversible reactions with hydrogen ions
• They remain unchanged regardless of pH changes

In acidic conditions, the equilibrium of indicator molecules tends to shift towards which form?

• Protonated form (HIn)
• Deprotonated form (In⁻)
• Both forms equally
• None of the above

How do indicators change color as the pH of the solution increases?

• They become more transparent
• They change from red to blue
• They change from blue to red
• They undergo a visible color change corresponding to the shift in equilibrium

What role does the pKa value of an indicator play in its color change behavior?

• It determines the temperature at which the color change occurs
• It affects the color of the indicator
• It influences the pH range over which the indicator changes color
• It has no impact on the indicator's behavior

Which form of an indicator predominates in acidic solutions?

• Protonated form (HIn)
• Deprotonated form (In⁻)
• Both forms equally
• None of the above

When does the equilibrium position shift to the RIGHT for an indicator?

• Low pH
• High pH
• Neutral pH
• Variable pH

What is the relationship between the acid form (HIn) and its conjugate base (In-)?

• They have the same color
• They are both strong acids
• Their colors change at the same pH
• They have different colors

When the indicator is pushed LEFT (acid colour form). There is a

• High pH
• Low pH
• Neutral pH
• Variable pH

If an indicator has a high pKa it

• Has a high concentration at equilibrium

• Has a low [H+] at equilibrium

• Has a high [H+] at equilibrium

• Has a low concentration at equilibrium