Class 10 chemistry Viva Voce Questions and Answers
Class 10 chemistry Viva Voce questions and answers are going to help you in the preparation of CBSE board examinations 2020-21. All questions of Class 10 chemistry Viva Voce questions are answered by a subject expert.All answers of VivacVoce questions of class 10 chemistry CBSE are also useful in competitive entrance examinations.
Q1.What is quick lime?
Ans. Quick lime is calcium oxide (CaO)
Q2.What is slaked lime?
Ans.slaked lime is calcium hydroxide (Ca(OH)2)
Q3.What is the nature of slaked lime?
Ans. It’s basic by nature.
Q4.What do you observe when water and quick lime is added in a beaker? Can you identify the type of reaction?
Ans.A fast and vigorous reaction place. The beaker becomes hot indicating its exothermic nature. It is an example of a combination reaction.
Q5.Write the basic chemical reaction involved in slaking of lime.
Q6.What is the colour of freshly prepared ferrous sulphate solution? State its common name in hydrated state.
Ans. Its colour is light green. Its called green vitriol.Chemical formula, FeSO4 .7H2O
Q7.What is the colour of ferric sulphate solution?
Ans. It is light brown in colour.
Q8.Name the type of reactions which takes place when ferrous sulphate crystals and calcium carbonate in heated. Write the balanced chemical reaction involved.
Ans. These are decomposition reactions.
Q9.What is blue Vitriol?
Ans. It is a copper sulphate pentahydrate, CuSO4 .5H2O.
Q10.Can you store copper sulphate solution in iron container?
Ans.No, We cannot store copper sulphate in iron container because iron being more reactive will displace copper and will change to iron sulphate.
Q11.What do you mean by activity series of metals?
Ans. List of metals written in an order where the most reactive metal lies at the top and the least reactive at the bottom,i.e.metals arranged in descending order of their reactivity s called reactivity or activity series of metals.
Q12.Name any two metals which are more reactive than iron?
Ans. Sodium and Aluminium
Q13.What will you observe if the copper filling is added to green colour ferrous sulphate solutions?
Ans. We will observe no change or reaction as iron can’t be displaced by less reactive copper from its salt solution.
Q14. A piece of magnesium is put into copper sulphate solutions. What would be the expected observation?
Ans. The blue colour of (CuSO4) copper sulphate solutions will fade and will finally turn colourless . The magnesium piece will get covered by the red-brown coating.
Q15.If a student is provided with three-piece of metals Zn, Cu and Ag each . Which one he/she will prefer to prepare hydrogen gas using dilute HCl?
Ans. The student will use the piece of Zn metal to produce hydrogen gas as only Zn is more reactive than hydrogen ad thus will displace hydrogen from HCl.
Q16. What is the name of the functional group of acetic acid?
As. Carboxylic acid (-COOH)
Q17.What is vinegar?
Ans. 5 TO 8% solution of acetic acid in water is known as vinegar.
Q18. What causes acidity of acetic acid?
Ans. In aqueous medium acetic acid releases ion, which is responsible for its acidic character.It is a weak acid.
Q19. Mention any two uses of acetic acid in industry.
Ans. (a) It is used as a coagulant in the rubber industry.
(b) Used in the food industry as vinegar.
Q20. What happens when ethanol is added to acetic acid in the presence of sulphuric acid. Write the chemical reaction.
Ans. A sweet-smelling substance, ethyl acetate is formed.(CH3COOC2H5).
Q21.Which gas is evolved when sodium bicarbonate is added to a test tube containing acetic acid?
Q22.Why pure acetic acid is called glacial acetic acid?
Ans. Pure acetic acid has freezing point at 16.6ºC ad it floats an water just like glaciers. Thus because of the similarity of appearance its called glacial acetic acid.
Q23.Why do we need to heat the reaction mixture in a water bath during esterification reaction?
Ans. We need to heat the reflection mixture to increase its rate which is otherwise slow. As the mixture contains alcohol, it is highly inflammable, hence we use water bath.
Q24.What is the need to add concentrated sulphuric acid in esterification reaction?
Ans. Concentrated sulphuric acid acts as a catalyst to increase the rate of reaction. Also, it’s a dehydrating agent ad so it absorbs by-product water, keeping the rate of reversible reaction in more ad more forward direction.
Q25. What makes water hard?
Ans. The presence of Ca²+ and Mg²+ salt in water make it hard.
Q26. What is hard water?
Ans. Water which does not form a good lather with soap solution is called hard water.
Q27. A student adds 1ml of soap solution in 5ml of water. He observes a foamy appearance inside the test tube. What does this signify?
Ans. The foam produced by the soap signifies good lather formation indicating softness of the water taken in the test tube.
Q28.If a soap solution is prepared in alcohol (ethanol) rather than water can we use that solution for cleaning grease from a piece of cloth?
Ans.In alcohol soap will be completely soluble, hence micelle formation will not take place which will hamper the cleansing action of soap. On the other hand alcohol will itself dissolve some grease and may clean the piece of cloth.
Q29.Define the temporary hardness of water?
Ans. The presence of calcium or magnesium in the form of bicarbonates causes temporary hardness of the water.
Q30.Why its called temporary hardness?
Ans. It is called temporary hardness as it can be easily removed by the boiling the hard water following by filtration or sedimentation.
On boiling the bicarbonates decompose into insoluble carbonates which can be separated by filtration.
Q31. How permanent hardness of water can be removed?
Ans. Permanent hardness of water ca e removed by boiling it with sodium carbonate(Na2CO3) or washing soda.O boiling the chlorides ad sulphates will covert to insoluble carbonates which ca e removed y filtration or sedimentation.
Q32.While conducting the experiment for hard water. Which will form more form, soap, or detergent?
Ans. The detergent will form more foam. Soap will form less foam but scum.
Q33.What is the role of HCl in the stomach?
Ans. HCl in the stomach is released by its wall and has two important functions.
(i) HCl kills the bacteria that exist in the food we have taken.
(ii) The main role of HCl is to maintain the pH value of the stomach suitable for the secretion of the enzymes
Q34.Why is baking soda added in food while cooking it?
Ans. The baking soda(NaHCO3) when added to food, after heating it produces carbon dioxide that aerates the food and thus changes the texture of food and cooks the food faster. When baking soda interacts with edible acids like tartaric acid (in tamarind) or oxalic acid(tomato) then the following reaction takes place
(NaHCO3) + H+(from acid) ⇒ CO2+H2O + Sodium salt of acid
Further formation of carbon dioxide causes the food to rise to make the food soft and spongy and thus food ingredients dissolved in each other quickly and completely.
Q35. What happens to acid and base in a water solution.
Ans. When we add acid to water, the following reaction occurs
ion can not exist alone, they form a covalent bond with a water molecule and forms hydronium ions
When the base is dissolved in water, the following reaction occurs
Bases generate hydroxide OH– in water, bases which are soluble in water are called alkalis
Q36.What do you mean by the catabolic process?
Ans. Catabolism means the metabolic activities which involve the breakdown of complex substances like glucose in cells is broken down into simpler substances(H2O and CO2).
Ans. The physical process of inhalation of oxygen and exhalation of carbon dioxide is called breathing.
Ans.Its a type of anaerobic respiration. It also releases CO2 as a by-product.
Q39.Why we use germinating seeds but not green leaves of a plant to demonstrate respiration.
Ans. Germinating seeds are under rapid growth hence they actively respire. On the other hand, green leaves of a plant will undergo photosynthesis also along with respiration. Thus it will utilize CO2 produced during respiration, hence the presence of CO2 may not be detected properly.
Q40. What are raw materials for respiration.
Q41.What is the full form of ATP.
Ans. Adenosine Triphosphate, it is an energy-rich molecule.
Q42.What are amphoteric oxides?
Ans. The type of oxide that reacts with acid as well as base is known as amphoteric oxide,as an example aluminium oxide and zinc oxide,both of them reacts with HCl and NaOH.
Q43. What do you understand by the pH value?
Ans. The pH value is the negative log of the concentration of hydrogen ions if the concentration of hydrogen ion is more,the lesser the value of pH as the value of pH of acids is lesser than the base.
Q44. What is the difference between an ionic bond and covalent bond.
Ans. When the atoms participating in chemical reaction losses or gains electrons,they forms ions, cation and anion. Both of oppositely charged ions stuck together form an ionic bond,as an example during the reaction of NaOH and HCl, NaCl is formed.
When electrons are shared by the atoms from each other,then kinds of bond created between them is known as covalent bond,as an example formation of CO2 from carbon and qxygen.
Follow us on in.pintrest.com future study point9891
NCERT solutions of class 10 science
Solutions of class 10 last years Science question papers
NCERT Solutions of Science and Maths for Class 9,10,11 and 12
NCERT Solutions of class 9 maths
|Chapter 1- Number System||Chapter 9-Areas of parallelogram and triangles|
|Chapter 2-Polynomial||Chapter 10-Circles|
|Chapter 3- Coordinate Geometry||Chapter 11-Construction|
|Chapter 4- Linear equations in two variables||Chapter 12-Heron’s Formula|
|Chapter 5- Introduction to Euclid’s Geometry||Chapter 13-Surface Areas and Volumes|
|Chapter 6-Lines and Angles||Chapter 14-Statistics|
|Chapter 7-Triangles||Chapter 15-Probability|
|Chapter 8- Quadrilateral|
NCERT Solutions of class 9 science
NCERT Solutions of class 10 maths
NCERT solutions of class 11 maths
|Chapter 1-Sets||Chapter 9-Sequences and Series|
|Chapter 2- Relations and functions||Chapter 10- Straight Lines|
|Chapter 3- Trigonometry||Chapter 11-Conic Sections|
|Chapter 4-Principle of mathematical induction||Chapter 12-Introduction to three Dimensional Geometry|
|Chapter 5-Complex numbers||Chapter 13- Limits and Derivatives|
|Chapter 6- Linear Inequalities||Chapter 14-Mathematical Reasoning|
|Chapter 7- Permutations and Combinations||Chapter 15- Statistics|
|Chapter 8- Binomial Theorem||Chapter 16- Probability|
NCERT solutions of class 12 maths
|Chapter 1-Relations and Functions||Chapter 9-Differential Equations|
|Chapter 2-Inverse Trigonometric Functions||Chapter 10-Vector Algebra|
|Chapter 3-Matrices||Chapter 11 – Three Dimensional Geometry|
|Chapter 4-Determinants||Chapter 12-Linear Programming|
|Chapter 5- Continuity and Differentiability||Chapter 13-Probability|
|Chapter 6- Application of Derivation||CBSE Class 12- Question paper of maths 2021 with solutions|
|Chapter 7- Integrals|
|Chapter 8-Application of Integrals|
ONLINE SHOPPING WITH A DEAL