When phenolphthalein is added to NaOH, the colour of the solution will become pink - Science and Technology 1


When phenolphthalein is added to NaOH, the colour of the solution will become _________.

  1. colourless
  2. red
  3. pink
  4. yellow



When phenolphthalein is added to NaOH, the colour of the solution will become pink

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2014-2015 (March)



Dilute NaOH can be tested with
(a) red litmus paper
(b) blue litmus paper
(c) lime water
(d) Na2CO3

  Column A   Column B
i eosin 1 losing hydrogen
ii oxidation 2 synthetic indicator
    3 losing oxygen
    4 natural indicator


From which plant is litmus paper or litmus solution obtained?

  1. Moss
  2. Rose
  3. Hibiscus
  4. Lichen

 Why should curd and sour substances not be kept in brass and copper vessels?

When acids react with metal, which gas is liberated?

The litmus paper or the litmus solution is obtained from ________ plant

(A) Moss

(B) Lichen

(C) Rose

(D) Hibiscus

 Complete and balance the followingchemicalequations:

NaHCO3 (S) + HCI (aq) →

Give chemical equation of the reaction involved.

What happens when an acid reacts with a metal carbonate? Explain with the help of an example. Write chemical equation of the reaction involved.

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


A solution reacts with marble chips to produce a gas which turns lime water milky. The solution contains:
(a) Na2SO4
(b) CaSO4
(c) H2SO4
(d) K2SO4

A solution reacts with zinc granules to give a gas which burns with a 'pop' sound. The solution contains:
(a) Mg(OH)2
(b) Na2CO3
(c) NaCl
(d) HCl

State one use of bleaching powder (other than bleaching).


Phenolphthalein is a synthetic type of indicator.

Choose the correct alternative and rewrite the following sentence.

Phenolphthalein is ___________ type of indicator. 

When _______________ is passed through fresh lime water, it turns milky.

Answer the following question:
What is the universal indicator? Does Mg (OH)2 react with sodium hydroxide? If not, why?

Write any four physical properties of acids.

Acids turn blue litmus paper to ______.

What is a neutralization reaction? Give an example.

In an attempt to demonstrate electrical conductivity through an electrolyte, the apparatus setup. Which among the following statement(s) is(are) correct?

  1. Bulb will not glow because electrolyte is not acidic
  2. Bulb will glow because NaOH is a strong base and furnishes ions for conduction.
  3. Bulb will not glow because circuit is incomplete
  4. Bulb will not glow because it depends upon the type of electrolytic solution

Acids present in fruits and vegetables are called ______ acids.

Vinegar is ______ in taste.

A salt may be ______.

Solutions of acids conduct ______.

______ change the colour of the indicators.

Which acid is present in milk?

Are all acids corrosive in nature? Name a few acids which are non-corrosive and may be part of our food.

Copper or brass cooking vessels are coated with tin metal. Why?

Take a clean test tube with a holder and pour some dilute hydrochloric acid. Add a few pieces of magnesium ribbon pieces slowly. What do you observe? Now show a burning match stick near the mouth of the test tube. Do you hear any sound? The gas burns with a pop sound. From this, it is observed that hydrogen gas has been formed due to the reaction between acid and metal.

What is the correct procedure for mixing acid and water? Why?

“All acids contain one or more hydrogen atoms, but not all substances containing hydrogen are acids.” Support this statement with examples.

______ & ______ metals do not react with HCl or HNO3.

The formula of bleaching powder is  ______.

The taste of acid is ______.

Write notes on the properties of acids.

The metal that will not produce hydrogen gas when reacted with dilute acids.


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