Read the passage carefully and answer the following questions from (i) to (v):

The use of a universal indicator, which is a mixture of several indicators, can be helpful in judging how strong a given acid or base is. The universal indicator shows different colours at different concentrations of hydrogen ions in a solution. Here is a scale for measuring hydrogen ion concentration in a solution, called pH scale. The ‘p’ in pH stands for potenz in German, meaning power. On the pH scale, we can measure pH from 0 (very acidic) to 14 (very alkaline).

pH should be thought of simply as a number which indicates the acidic or basic nature of a solution. Higher the hydronium ion concentration, lower is the pH value.

The pH of a neutral solution is 7. Values less than 7 on the pH scale represent an acidic solution. As the pH value increases from 7 to 14, it represents an increase in $O{H}^{-}$ ion concentration in the solution, that is, increase in the strength of alkali.

(i) When hydrogen chloride gas is prepared on a humid day, the gas is usually passed through the guard tube containing calcium chloride. The role of calcium chloride taken in the guard tube is to:

Read the passage carefully and answer the following questions from (i) to (v):

The use of a universal indicator, which is a mixture of several indicators, can be helpful in judging how strong a given acid or base is. The universal indicator shows different colours at different concentrations of hydrogen ions in a solution. Here is a scale for measuring hydrogen ion concentration in a solution, called pH scale. The ‘p’ in pH stands for potenz in German, meaning power. On the pH scale, we can measure pH from 0 (very acidic) to 14 (very alkaline).

pH should be thought of simply as a number which indicates the acidic or basic nature of a solution. Higher the hydronium ion concentration, lower is the pH value.

The pH of a neutral solution is 7. Values less than 7 on the pH scale represent an acidic solution. As the pH value increases from 7 to 14, it represents an increase in $O{H}^{-}$ ion concentration in the solution, that is, increase in the strength of alkali.

(ii) Which of the following statements is correct about an aqueous solution of an acid and of a base?

(A) Higher the pH, stronger the acid
(B) Higher the pH, weaker the acid
(C) Lower the pH, stronger the base
(D) Lower the pH, weaker the base

Read the passage carefully and answer the following questions from (i) to (v):

The use of a universal indicator, which is a mixture of several indicators, can be helpful in judging how strong a given acid or base is. The universal indicator shows different colours at different concentrations of hydrogen ions in a solution. Here is a scale for measuring hydrogen ion concentration in a solution, called pH scale. The ‘p’ in pH stands for potenz in German, meaning power. On the pH scale, we can measure pH from 0 (very acidic) to 14 (very alkaline).

pH should be thought of simply as a number which indicates the acidic or basic nature of a solution. Higher the hydronium ion concentration, lower is the pH value.

The pH of a neutral solution is 7. Values less than 7 on the pH scale represent an acidic solution. As the pH value increases from 7 to 14, it represents an increase in  ion concentration in the solution, that is, increase in the strength of alkali.

(iii) An aqueous solution turns red litmus solution blue. Excess addition of which of the following solutions would reverse the change?

Read the passage carefully and answer the following questions from (i) to (v):

The use of a universal indicator, which is a mixture of several indicators, can be helpful in judging how strong a given acid or base is. The universal indicator shows different colours at different concentrations of hydrogen ions in a solution. Here is a scale for measuring hydrogen ion concentration in a solution, called pH scale. The ‘p’ in pH stands for potenz in German, meaning power. On the pH scale, we can measure pH from 0 (very acidic) to 14 (very alkaline).

pH should be thought of simply as a number which indicates the acidic or basic nature of a solution. Higher the hydronium ion concentration, lower is the pH value.

The pH of a neutral solution is 7. Values less than 7 on the pH scale represent an acidic solution. As the pH value increases from 7 to 14, it represents an increase in  ion concentration in the solution, that is, increase in the strength of alkali.

(iv) The pH of a solution of HCl is 4. This shows that the molarity of the solution is:

Read the passage carefully and answer the following questions from (i) to (v):

The use of a universal indicator, which is a mixture of several indicators, can be helpful in judging how strong a given acid or base is. The universal indicator shows different colours at different concentrations of hydrogen ions in a solution. Here is a scale for measuring hydrogen ion concentration in a solution, called pH scale. The ‘p’ in pH stands for potenz in German, meaning power. On the pH scale, we can measure pH from 0 (very acidic) to 14 (very alkaline).

pH should be thought of simply as a number which indicates the acidic or basic nature of a solution. Higher the hydronium ion concentration, lower is the pH value.

The pH of a neutral solution is 7. Values less than 7 on the pH scale represent an acidic solution. As the pH value increases from 7 to 14, it represents an increase in  ion concentration in the solution, that is, increase in the strength of alkali.

(v) Two aqueous solutions P and Q have pH of 5 and 13 respectively. The correct inference is that:

Read the passage carefully and answer the following questions from (i) to (v):

Vedanshi and Krati are working in the lab. During the experiment of determining the reactivity of acids and bases, the test tube containing chemical ‘X’ cracked and the liquid inside produced blisters on the skin of Krati. The pH strip turned blue to red with the reaction to the liquid. Vedanshi immediately called her teacher for help, and first aid was provided to Krati.

(i) What could be the possible liquid be present in test tube?

Read the passage carefully and answer the following questions from (i) to (v):

Vedanshi and Krati are working in the lab. During the experiment of determining the reactivity of acids and bases, the test tube containing chemical ‘X’ cracked and the liquid inside produced blisters on the skin of Krati. The pH strip turned blue to red with the reaction to the liquid. Vedanshi immediately called her teacher for help, and first aid was provided to Krati.

 (ii) The following list includes the possible first aid for the laboratory accidents:

1. Thoroughly rinse the affected area with water.

2. Having medicines without prescribing the doctor.

3. Consult the doctor immediately.

4. To go outside the lab, preferably in an open area.

5. Not telling the teacher and other elders or they might scold you.

Read the passage carefully and answer the following questions from (i) to (v):

Vedanshi and Krati are working in the lab. During the experiment of determining the reactivity of acids and bases, the test tube containing chemical ‘X’ cracked and the liquid inside produced blisters on the skin of Krati. The pH strip turned blue to red with the reaction to the liquid. Vedanshi immediately called her teacher for help, and first aid was provided to Krati.

(iii)The given graph below is plotted against pH and $H^{+}$ concentration.

In the experiment, Krati and Vedanshi listed the chemicals in list A and B. Which of the following is correct?

Read the passage carefully and answer the following questions from (i) to (v):

Vedanshi and Krati are working in the lab. During the experiment of determining the reactivity of acids and bases, the test tube containing chemical ‘X’ cracked and the liquid inside produced blisters on the skin of Krati. The pH strip turned blue to red with the reaction to the liquid. Vedanshi immediately called her teacher for help, and first aid was provided to Krati.

(iv) Krati detected the pH of four unknown solutions A, B, C, and D as follows: 11, 5, 7, and 2 respectively, and noted down her results.

1. C is neutral in nature.

2. On reacting A and D, water is liberated.

3. A and C are basic in nature.

4. B and D react to form hydrogen gas.

Read the passage carefully and answer the following questions from (i) to (v):

Vedanshi and Krati are working in the lab. During the experiment of determining the reactivity of acids and bases, the test tube containing chemical ‘X’ cracked and the liquid inside produced blisters on the skin of Krati. The pH strip turned blue to red with the reaction to the liquid. Vedanshi immediately called her teacher for help, and first aid was provided to Krati.

(v) What does the following activity represent?

Read the passage carefully and answer the following questions from (i) to (v):

A compound C of sodium forms a white powder. It is a constituent of baking powder and is used in some antacids. When heated, it gives a compound D which is anhydrous and absorbs water to become a hydrated salt. When this salt is kept in the open air, it loses water molecules in a process called efflorescence. When dissolved in water, it forms a strong base and a weak acid F.

(i) Which of the following is compound C?

Read the passage carefully and answer the following questions from (i) to (v):

A compound C of sodium forms a white powder. It is a constituent of baking powder and is used in some antacids. When heated, it gives a compound D which is anhydrous and absorbs water to become a hydrated salt. When this salt is kept in the open air, it loses water molecules in a process called efflorescence. When dissolved in water, it forms a strong base and a weak acid F.

(ii) Which of the following is compound D?

Read the passage carefully and answer the following questions from (i) to (v):

A compound C of sodium forms a white powder. It is a constituent of baking powder and is used in some antacids. When heated, it gives a compound D which is anhydrous and absorbs water to become a hydrated salt. When this salt is kept in the open air, it loses water molecules in a process called efflorescence. When dissolved in water, it forms a strong base and a weak acid F.

(iii) What is the nature of the solution formed by dissolving D in water?

Read the passage carefully and answer the following questions from (i) to (v):

A compound C of sodium forms a white powder. It is a constituent of baking powder and is used in some antacids. When heated, it gives a compound D which is anhydrous and absorbs water to become a hydrated salt. When this salt is kept in the open air, it loses water molecules in a process called efflorescence. When dissolved in water, it forms a strong base and a weak acid F.

(iv) Which among the following is compound F?

Read the passage carefully and answer the following questions from (i) to (v):

A compound C of sodium forms a white powder. It is a constituent of baking powder and is used in some antacids. When heated, it gives a compound D which is anhydrous and absorbs water to become a hydrated salt. When this salt is kept in the open air, it loses water molecules in a process called efflorescence. When dissolved in water, it forms a strong base and a weak acid F.

(v) Sodium carbonate is a basic compound because it is a salt of a:

Read the passage carefully and answer the following questions from (i) to (v):

Marble’s popularity began in ancient Rome and Greece, where white and off-white marble were used to construct a variety of structures, from hand-held sculptures to massive pillars and buildings.

(i) The substance not likely to contain $CaC{O}_3$ is:

Read the passage carefully and answer the following questions from (i) to (v):

Marble’s popularity began in ancient Rome and Greece, where white and off-white marble were used to construct a variety of structures, from hand-held sculptures to massive pillars and buildings.

(ii) A student added 10 g of calcium carbonate in a rigid container, secured it tightly and started to heat it. After some time, an increase in pressure was observed, the pressure reading was then noted at intervals of 5 mins and plotted against time, in a graph as shown. During which time interval did maximum decomposition take place?

Read the passage carefully and answer the following questions from (i) to (v):

Marble’s popularity began in ancient Rome and Greece, where white and off-white marble were used to construct a variety of structures, from hand-held sculptures to massive pillars and buildings.

(iii) Gas A, obtained above is a reactant for a very important biochemical process which occurs in the presence of sunlight. Identify the name of the process:

Read the passage carefully and answer the following questions from (i) to (v):

Marble’s popularity began in ancient Rome and Greece, where white and off-white marble were used to construct a variety of structures, from hand-held sculptures to massive pillars and buildings.

(iv) Marble statues are corroded or stained when they repeatedly come into contact with polluted rain water. Identify the main reason.

Read the passage carefully and answer the following questions from (i) to (v):

Marble’s popularity began in ancient Rome and Greece, where white and off-white marble were used to construct a variety of structures, from hand-held sculptures to massive pillars and buildings.

(v) Calcium oxide can be reduced to calcium by heating with sodium metal. Which compound would act as an oxidizing agent in the above process?

Read the passage carefully and answer the following questions from (i) to (v):

Common edible salt, NaCl (Sodium Chloride) obtained from seawater or from lakes contains many impurities such as sulphates of sodium and magnesium along with chlorides of calcium and magnesium. The chlorides of these metals are particularly undesirable being deliquescent in nature.

A saturated solution of salt in a minimum quantity of water is prepared and insoluble impurities are filtered off. HCl gas is then passed through the saturated solution and the crystals of pure NaCl separate out. The soluble impurities remain in the solution. Pure crystals of NaCl are filtered, washed, and dried.

(i) Choose the correct statement:

Read the passage carefully and answer the following questions from (i) to (v):

Common edible salt, NaCl (Sodium Chloride) obtained from seawater or from lakes contains many impurities such as sulphates of sodium and magnesium along with chlorides of calcium and magnesium. The chlorides of these metals are particularly undesirable being deliquescent in nature.

A saturated solution of salt in a minimum quantity of water is prepared and insoluble impurities are filtered off. HCl gas is then passed through the saturated solution and the crystals of pure NaCl separate out. The soluble impurities remain in the solution. Pure crystals of NaCl are filtered, washed, and dried.

(ii) Nature of the aqueous solution of common salt is:

Read the passage carefully and answer the following questions from (i) to (v):

Common edible salt, NaCl (Sodium Chloride) obtained from seawater or from lakes contains many impurities such as sulphates of sodium and magnesium along with chlorides of calcium and magnesium. The chlorides of these metals are particularly undesirable being deliquescent in nature.

A saturated solution of salt in a minimum quantity of water is prepared and insoluble impurities are filtered off. HCl gas is then passed through the saturated solution and the crystals of pure NaCl separate out. The soluble impurities remain in the solution. Pure crystals of NaCl are filtered, washed, and dried.

(iii) Which of the following compounds is alkaline in an aqueous medium?

Read the passage carefully and answer the following questions from (i) to (v):

Common edible salt, NaCl (Sodium Chloride) obtained from seawater or from lakes contains many impurities such as sulphates of sodium and magnesium along with chlorides of calcium and magnesium. The chlorides of these metals are particularly undesirable being deliquescent in nature.

A saturated solution of salt in a minimum quantity of water is prepared and insoluble impurities are filtered off. HCl gas is then passed through the saturated solution and the crystals of pure NaCl separate out. The soluble impurities remain in the solution. Pure crystals of NaCl are filtered, washed, and dried.

(iv) Adding common salt to water will result in:

Read the passage carefully and answer the following questions from (i) to (v):

Common edible salt, NaCl (Sodium Chloride) obtained from seawater or from lakes contains many impurities such as sulphates of sodium and magnesium along with chlorides of calcium and magnesium. The chlorides of these metals are particularly undesirable being deliquescent in nature.

A saturated solution of salt in a minimum quantity of water is prepared and insoluble impurities are filtered off. HCl gas is then passed through the saturated solution and the crystals of pure NaCl separate out. The soluble impurities remain in the solution. Pure crystals of NaCl are filtered, washed, and dried.

(v) Examine few statements regarding NaCl:

I. It is prepared by Chlor-alkali process
II. It is a white crystalline substance
III. It also exists in the form of rocks called rock salt
IV. It is a neutral salt with a pH value = 7

Read the passage carefully and answer the following questions from (i) to (v):

Reshma broke her leg in an accident. She went to see Dr. Sant Prakash. On examination, Dr. Prakash mixed the white powder in water and applied to her leg along with the cotton and gauze. After a while, it turned into white, solid, hard mass. He said that it would support her fractured bone in the right position.

(i) After treatment, the doctor repacked the white powder back into a moisture-proof, airtight container. Why?

Read the passage carefully and answer the following questions from (i) to (v):

Reshma broke her leg in an accident. She went to see Dr. Sant Prakash. On examination, Dr. Prakash mixed the white powder in water and applied to her leg along with the cotton and gauze. After a while, it turned into white, solid, hard mass. He said that it would support her fractured bone in the right position.

(ii) What is ‘white, solid hard mass’ called as?

Read the passage carefully and answer the following questions from (i) to (v):

Reshma broke her leg in an accident. She went to see Dr. Sant Prakash. On examination, Dr. Prakash mixed the white powder in water and applied to her leg along with the cotton and gauze. After a while, it turned into white, solid, hard mass. He said that it would support her fractured bone in the right position.

(iii) The reaction involved in the formation of white mass is:

Read the passage carefully and answer the following questions from (i) to (v):

Reshma broke her leg in an accident. She went to see Dr. Sant Prakash. On examination, Dr. Prakash mixed the white powder in water and applied to her leg along with the cotton and gauze. After a while, it turned into white, solid, hard mass. He said that it would support her fractured bone in the right position.

(iv) The graph shows the porosity and expansion of plaster with respect to water content. At what temperature would the reaction occur?

Read the passage carefully and answer the following questions from (i) to (v):

Reshma broke her leg in an accident. She went to see Dr. Sant Prakash. On examination, Dr. Prakash mixed the white powder in water and applied to her leg along with the cotton and gauze. After a while, it turned into white, solid, hard mass. He said that it would support her fractured bone in the right position.

(v) Study the following reaction and choose the correct option:
 

$CaS{O}_4\cdot 1/2H_{2}O+3/2H_{2}O⟶CaS{O}_4\cdot 2H_{2}O$