Class 11th| Chemistry Viva-Voce Questions Answers.

By -
Q1. Define boiling point of a liquid ?

Ans. The boiling point of a liquid is the temperature at which its vapour pressure is equal to the atmospheric pressure and the liquid starts boiling.

Q2. What is the importance of boiling point?

Ans. Every pure liquid has a fixed boiling point . Impurities raise the boiling point of a liquid. Therefore from boiling point determination one can find out whether a substance is pure or not.

Q3. Why should the open-end of the capillary be kept above the liquid level?

Ans. Otherwise liquid will enter into the capillary tube and the substances will dissolve.

Q4. Can the same organic liquid boil at different temperatures?

Ans. Yes, because the boiling point of liquid varies with the external pressure.

Q5.If a small amount of non-volatile is added to a pure liquid ,would it boil as its boiling point?

Ans.No, the boiling point will be slightly higher.

Q6. What is the effect of pressure on boiling point?

Ans. The boiling point decreases with decrease in pressure.

Q7. What is the approximate temperature at which the water boils in a pressure cooker?

Ans. The water boils at about 120°to 125° in a pressure cooker.

Q8. Why is pumice stone added in the liquid while determining its boiling point?

Ans. Pumice stone is used to avoid bumping .

Q9. Can HCL or HNO³ be used of H²SO⁴?

Ans. No, HCL and HNO³ have low boiling points. Moreover, HNO³ gives brown fumes when heated.

Q10.Why does a liquid boil?

Ans. When we heat a liquid, the kinetic energy of molecules increases and its vapour pressure increases. When the vapour pressure of liquid becomes equal to the atmosphere pressure , becomes liquid starts boiling.

Comments

Post a Comment

Popular posts from this blog

Reproduction class 12th /Importance of reproduction and basic features of reproduction .NEET/BIOLOGY CLASS 12th CBSE/NCERT 2024_2025 Important topics.

By -
Reproduction: It is a biological process in which an organism produces number of individuals or offsprings of  similar type. IMPORTANCE OF REPRODUCTION: 1) Continvity of species means group of individuals which are similar in morphology (external features) functions, behavior but they can reproduce sucessfully in natural condition. 2) It maintaines chromosome number. 3) It helps in replacement of organisms. BASIC FEATURES OF REPRODUCTION: Before reproduction these features are important. 1) Replication of DNA molecule means forming two or duplicate DNA copies. 2)Formation of RNA molecule, proteins, cells, cell organelles and other biochemicals. 3) Cell division [Mitosis_asexual/Meiosis_sexual]. 4) It helps in formation of separate reproductive units (Male/Female). 5) Formation of offsprings is due to combination of reproductive units. CELL DIVISION: It is the process by which a parent cell divides into two or more daughter cells .On the basis of cell division are two types of cell...
Read more

Reproduction

By -
Reproduction. It is a biological process  in which an organism produces number of individuals or offsprings of similar type. Importance of reproduction. 1 . Continuity of species [means group of  individuals which are similar in morphology (external features) functions, behavior but they can reproduce sucessfully in natural condition. 2.It maintains Chromosome number. 3. It helps in existence of life. 4.It helps in replacement of organisms. Basic feature of reproduction. Before reproduction these features are important . 1. Replication of DNA molecule means forming two or duplicate DNA copies . 2. Formation of RNA molecule,proteins ,cells , cell organelles and other biochemicals. 3.Cell division [Mitosis -asexual /Meiosis sexual.] 4. It helps in formation of separate reproductive units (Male/Female). 5. Formation of offsprings is due to combination of reproductive units. Cell Division . It is the process by which a parent cell divides into two or more daughter cells . On the b...
Read more

Why NaCl give s a white precipitate with AgNO³ solution but CCl⁴ does not?

By -
Q1.Why NaCl give s a white precipitate with AgNO³ solution but CCl⁴ does not? Ans. NaCl is an  ionic conpound and hence gives Cl‐ions in the solution which combine with Ag+ ions given by AgNO³ to fom a white precipitate of AgCl but CCl⁴ is a covalent compound and does not give Cl‐ions . Q2.Why reaction between NaCl and AgNO³  is very fast but reaction between H² and Cl² is slow? Ans. NaCl and AgNO³ are ionic compounds, In solution, NaCl gives Na+ and Cl_ ions and AgNO³, gives Ag+ and NO‐³ions. The oppositely charged Ag+and Cl+ ions combine immediately. The reaction betwecn H2 and Cl2 involves breaking of covalent bonds which requires energy.
Read more