Indicators

Q.

What are common indicators?

Q.

Sulphur dioxide is dissolved in water. The solution is tested for acidic nature. What are the changes you will observe when you dip a litmus paper in the solution?

1. Red litmus turns blue

2. Blue litmus turns to red

3. No change occurs

4. Blue litmus turns to yellow.

Q.

Which of the following is an acid-base indicator?

1. Vinegar

2. Lime water

3. Turmeric

4. Baking soda

Q. What is the effect of potassium hydroxide solution on litmus paper?

Q.

Is ${\mathrm{KMnO}}_4$ a self-indicator?

Q.

The most commonly used natural indicator is ______________ .

Q. What is the effect of potassium hydroxide solution on litmus paper?

1. Turns blue litmus to red
2. Turns red litmus to blue
3. Turns red litmus to green
4. Turns blue litmus to green

Q.

Which of the following is the property of phenol?

1. 
   

   Weak acid

2. 
   

   High volatile

3. 
   

   White crystalline powder.

4. 
   

   All of these

Q.

Which of the following is the property of phenol?

1. 
   

   Weak acid

2. 
   

   High volatile

3. 
   

   White crystalline powder.

4. 
   

   All of these

Q. Three test tubes contains different solutions and are labelled as A, B and C. The table below shows the observations when red and blue litmus papers were dipped in these test tubes.
Analyse the table given below and choose the correct options from the following.

$\begin{array}{cccc}& \text{Test tube A}& \text{Test tube B}& \text{Test tube C}\\ \text{Red Litmus}& \text{No change}& \text{No change}& \text{No change}\\ \text{Blue Litmus}& \text{Red}& \text{No change}& \text{Red}\end{array}$

1. The sample in test tube B is neutral
2. The sample in test tube C is acidic
3. The sample in test tube A is acidic
4. The sample in test tube A is neutral

Q. Red cabbage extract is a synthetic indicator.

1. True
2. False

Q.

Define indicator.

Q. Which among following will not help to test the acid or base?

1. Red cabbage
2. pH paper
3. Filter paper
4. Turmeric

Q. Which of the following is a naturally occuring indicator?

1. Phenolphthalein
2. Turmeric
3. Methyl orange
4. Methyl red