Tag: chemistry

Quizzes (490) Questions (9892)

Questions Related to chemistry

Multiple choice reactions of acids and bases properties of acids and bases acids, bases and salts acids and bases chemistry

Baking soda turns:

  1. turmeric to red

  2. purple-cabbage juice to green

  3. red litmus to blue

  4. all of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Turmeric, purple cabbage juice (containing anthocyanin), and litmus paper all act as indicators which help us to detect whether a particular substance is acidic or basic.

In basic medium, turmeric changes it's colour to red, purple-cabbage juice turns to green and red litmus turns to blue.
Baking soda/Sodium carbonate $Na _2CO _3$ is basic in nature and thus causes the above changes in the indicators.
Hence, the correct answer is option (D).

Multiple choice reactions of acids and bases properties of acids and bases acids, bases and salts acids and bases chemistry

China rose indicator is turned green by a certain solution. The solution is:

  1. acidic

  2. basic

  3. neutral

  4. all of these

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

An indicator is usually a weak acid or a weak base which changes colour in acidic or basic solutions.  The pigment anthocyanin present in the china rose flower makes its solution an indicator.
China rose solution gives dark pink colour with acid and green colour with base.

Multiple choice reactions of acids and bases properties of acids and bases acids, bases and salts acids and bases chemistry

Which of the following equation represents action of alkali on metal?

  1. $Zn+2NaOH\rightarrow Na _2ZnO _2+H _2$
  2. $Zn+2KOH\rightarrow K _2ZnO _2+H _2$
  3. $Pb+2KOH\rightarrow K _2PbO _2+H _2$

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Alkali reacts with hot concentrated caustic alkalies to give corresponding soluble salt and liberate hydrogen.

Multiple choice reactions of acids and bases properties of acids and bases acids, bases and salts acids and bases chemistry

Which of the following equation is correct for action of alkali on aluminium?

  1. $2Al+2NaOH+2H _2O\rightarrow2NaAlO _2+3H _2$
  2. $2Al+2KOH+2H _2O\rightarrow2KAlO _2+3H _2$
  3. $Al+NaOH+H _2O\rightarrow NaAlO _2+H _2$

  4. Both A and B
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

$2Al+2NaOH+2H _2O\rightarrow2NaAlO _2+3H _2$ and $2Al+2KOH+2H _2O\rightarrow2KAlO _2+3H _2$ 

Multiple choice reactions of acids and bases properties of acids and bases acids, bases and salts acids and bases chemistry

Which of the following is used for dissolution of gold ? 

  1. Hydrochloric acid

  2. Sulphuric acid

  3. Nitric acid

  4. Aqua regia
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Gold,palladium,gallium are all noble metals which are dissolved in aqua regia. It is also known as royal water which is a mixture of hydrochloric acid and nitric acid in the ratio of 3:1 respectively.

Multiple choice reactions of acids and bases properties of acids and bases acids, bases and salts acids and bases chemistry

Which of the following acid is used in fire extinguishers?

  1. Hydrochloric acid

  2. Sulphuric acid

  3. Nitric acid

  4. Oxalic acid
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Sulphuric acid is non flammable so soda acid is most common fire extinguisher. Carbon dioxide is liberated by the action of sulphuric acid on baking soda or sodium bicarbonate. This increases the percentage of carbon dioxide in air. Due to this the supply of air is cut off and fire is extinguished.

Multiple choice reactions of acids and bases properties of acids and bases acids, bases and salts acids and bases chemistry

Which of  the following acids is called the king of the acids?

  1. Acetic acid

  2. Phosphoric acid

  3. Oxalic acid

  4. Sulphuric acid
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Sulphuric acid is diprotic acid and shows different properties depending upon its concentration. It is a strong acid and in concentrated form it has strong dehydrating and oxidising properties. It has large number of applications. In almost all industrial processes sulphuric acid is used,in production of lead acid batteries,production of fertilizers,in chemistry labs,petroleum refining and production of paper. So it is called as the king of all acids.