Litmus Test

Q.

Name the reaction takes place when ethanoic acid reacts with ethanol.

Q.

Dry hydrogen chloride gas does not turn blue litmus to red whereas hydrochloric acid does. Why?

Q. When hydrogen chloride gas is passed through a litmus solution, its colour changes to .

1. red
2. blue
3. purple
4. yellow

Q.

$HCl$ gas turns blue litmus paper red - True or False?

1. True

2. False

Q.

State the reason for exhibiting acidic character by dry $\mathrm{HCl}$gas / $\mathrm{HCl}$solution.

Q.

When a blue litmus paper is put in an acidic Solution, it turns red. Can the red litmus which has been formed used to indicate basicity?

In other words, can litmus paper which has changed its colour once be reused?

Q. Question 10
Equal lengths of magnesium ribbons are taken in test tubes A and B. Hydrochloric acid $\text{HCl}$ is added to test tube A, while acetic acid $\left({\text{CH}}_3\text{COOH}\right)$ is added to test tube B. In which test tube will the fizzing occur more vigorously and why?

Q.

a) What is universal indicator .

b) What is the chemical equation involved in the preparation of sodium hydroxide. Name the process.

c) Give reason for; Dry hydrogen chloride gas does not turn blue litmus red whereas dilute hydrochloric.

Q. What change would you observe on adding:
1) Blue litmus solution to an aqueous solution of washing soda
2) Red litmus solution to an aqueous solution of washing soda

Q. Why does dry $HCl$ gas not change the colour of dry litmus paper?

Q.

Identify the effect of dry hydrogen chloride gas on litmus paper:

1. Turn red litmus to black

2. No effect on litmus paper

3. Turns red litmus to blue

4. Turns blue litmus to red

Q. X reacts with Zn metal and produce X zincate and hydrogen gas. What affect does X has on turmeric solution?

1. No change
2. It turns blue
3. It turns reddish brown
4. Its smell vanishes

Q. A colourless gas is dissolved in water and the resulting solution turns red litmus blue. Which of the following gases shows this type of reaction?

1. $HCl$
2. $H_{2}S$
3. ${NH}_3$
4. ${SO}_2$

Q.

What will you observe if hydrogen chloride gas is passed through blue litmus solution?

1. Red

2. Blue

3. White

4. Colourless

Q.

$HCl$ gas turns blue litmus paper red - True or False?

1. True

2. False

Q. With the help of labelled diagrams, describe an activity to show that acids produce ions only in aqueous solutions.

Q.

Why does not dry $HCl$ gas change the colour of the dry litmus paper?

1. Dry HCl gas does not release $O{H}^{-}$ ions

2. Dry HCl gas releases $O{H}^{-}$ ions

3. Dry HCl gas releases $H^{+}$ ions

4. Dry HCl gas does not release $H^{+}$ ions

Q. Thus, colourless mixture contains ___________.

1. ${ZnCl}_2,NaOH$
2. ${AlCl}_3,NaCl$
3. ${AlCl}_3,NaOH$
4. ${CrCl}_3,NaOH$

Q. Considering the following observations, solutions A and B contain oxide and oxide, respectively.

1. non-metallic
2. neutral
3. metallic
4. noble