Salts/Compounds Colour
1. Potassium dichromate, K₂Cr₂O₇ Orange
2. Potassium permanganate, KMnO₄ Violet
3. Ferric tetra-oxide, Fe₃O₄ Black
4. Ferrous sulphate, FeSO₄.7H₂O Green
5. Ferric sulphate, Fe₂(SO₄)₃ Yellow
6. Ferric hydroxide, Fe(OH)₂ Green
Q1: By what other name is the unit joule/coulomb called ?
Answer: Volt
Q2: Which of the following statements correctly defines a volt ?
(a) a volt is a joule per ampere.
(b) a volt is a joule per coulomb.
Answer: (b) a volt is a joule per coulomb.
Q3: (a) What do the letters p.d. stand for ?
(b) Which device is used to measure p.d. ?
Answer:
(a) p.d. stands for potential difference.
(b) Voltmeter is used to measure p.d.
Chapter: Life Processes (NCERT Book Activity 6.1)
Activity Steps
Step 1: Take a potted plant with variegated leaves – for example, a money plant or croton.
Step 2: Keep the plant in a dark room for three days so that all the starch gets used up.
Step 3: Now keep the plant in sunlight for about six hours.
Step 4: Pluck a leaf from the plant. Mark the green areas in it and trace them on a sheet of paper.
Step 5: Dip the leaf in boiling water for a few minutes.
Step 6: After this, immerse it in a beaker containing alcohol.
Step 7: Carefully place the above beaker in a water bath and heat till the alcohol begins to boil.
What happens to the colour of the leaf? What is the colour of the solution?
Step 8: Now dip the leaf in a dilute solution of iodine for a few minutes.
Take out the leaf and rinse off the iodine solution.
Observe the colour of the leaf and compare this with the tracing of the leaf done in the beginning.
What can you conclude about the presence of starch in various areas of the leaf?
Learning is a continual process. To improve scores, the best way is to learn and practice. Solving question papers help students to evaluate their knowledge and familarise with different types of question patterns being asked in examination.
Eduvictors provides CBSE Previous Year Papers and Sample Question Papers for Class Class 10 Maths, Science, Social, English, Hindi and Sanskrit with/without solutions to help students in their board exam preparation.
1. Buy Most Likely Question Bank - Science: CBSE Class 10 for 2021 Examination
Here attached the Science Sample Question Paper (2020-2021).
Assertion and Reasoning based questions are a bit tricky. You should be able to distinguish whether the assertion is well connected to the reason or these are just random facts. Read both statements carefully, and check if both statements are factually or logically correct or not. If both are correct, then try to check if both are well connected to each other or not.
The questions below consist of statements of an Assertion and a Reason. Use the following key to choose an appropriate answer:
Learning is a continual process. To improve scores, the best way is to learn and practice. Solving question papers help students to evaluate their knowledge and familarise with different types of question patterns being asked in examination.
Eduvictors provides CBSE Previous Year Papers and Sample Question Papers for Class Class 10 Maths, Science, Social, English, Hindi and Sanskrit with/without solutions to help students in their board exam preparation.
1. Buy Most Likely Question Bank - Science: CBSE Class 10 for 2021 Examination
Here attached the Science Sample Question Paper (2020-2021).
Learning is a continual process. To improve scores, the best way is to learn and practice. Solving question papers help students to evaluate their knowledge and familarise with different types of question patterns being asked in examination.
Eduvictors provides CBSE Previous Year Papers and Sample Question Papers for Class Class 10 Maths, Science, Social, English, Hindi and Sanskrit with/without solutions to help students in their board exam preparation.
1. Buy Most Likely Question Bank - Science: CBSE Class 10 for 2021 Examination
Here attached the Science Sample Question Paper (2020-2021) published by Dir. of Education (Delhi).
Based on chemical properties, all compounds can be classified as acids, bases and salts. To identify acids and bases, indicators are used. This video talks about types of indicators i.e. natural, synthetic and olfactory. Examples of indicators and related questions are also covered.
The first chapter of Chemistry talks about chemical reactions and equations. In a chemical reaction, reactants are transformed into products. In this series, the part-4 video discusses:
- corrosion
- examples of corrosion (good vs bad)
- methods to prevent corrosion
- rancidity
- methods to prevent rancidity
Learning is a continual process. To improve scores, the best way is to learn and practice. Solving question papers help students to evaluate their knowledge and familarise with different types of question patterns being asked in the examination.
Eduvictors provides CBSE Previous Year Papers and Sample Question Papers for Class 10 Maths, Science, Social, English, Hindi and Sanskrit with/without solutions to help students in their board exam preparation.
1. Buy CBSE All In One Science Class 10 for 2021 Exam
Here attached the Chemistry Sample Question Paper (2020-2021) for your self-evaluation.
In each of the following questions, a statement of Assertion is given by the corresponding statement of Reason. Of the statements, mark the correct answer as.
(a) If assertion is true and reason is correct explanation of assertion.
(b) If assertion is true but reason is false.
(c) If assertion is false but reason is true.
(d) If both are false.
Q1:
Assertion: We detect the smell of agarbati (incense stick)
Reason: Smell is detected by phono receptors of nose, which further relay impulses to the brain.
1. Why does not a wall immediately acquire a white colour when a coating of slaked lime is applied on it ?
2. Define displacement reaction with one example.
3. Identify the most reactive and least reactive metal : Al, K, Ca, Au.
4. Which of the following is a combination reaction and which is a displacement reaction ?
(a) Cl₂ + 2KI ——–> 2KCl + I₂
(b) 2K + Cl₂ ——–> 2KCl.
5. What is the difference between the following two reactions ?
(a) Mg + 2HCl ——–> MgCl2 + H2
(b) NaOH + HCl ——–> NaCl + H2O.
6. Identify the compound which is oxidised in the following reaction
H₂S + Br₂ ———–> 2HBr + S.
7. What happens chemically when quick lime is added to water ?
Q1. A green layer is gradually formed on a copper plate left exposed to air for a week in a bathroom. What could this green substance be?
Answer. It is due to the formation of basic copper carbonate [CuCO₃.Cu(OH)₂].
Q2. Why are elements of Group IA i.e. H, Li, Na, K, Cs and Fr called alkali metals?
Answer. Because oxides of these elements dissolve in water to give alkali or soluble hydroxides.
Q3. A non-metal X exists in two different forms Y and Z. Y is the hardest natural substance, whereas Z is a good conductor of electricity. Identify X, Y and Z.
Answer. ‘X’ is carbon, ‘Y’ is diamond as it is the hardest natural substance and ‘Z’ is graphite as it is good conductor of electricity.
Open Circuit
An open circuit implies that the two points are externally disconnected, which is equivalent to a resistance R = ∞ . This means that theoretically no current(I = 0) can flow between the two terminals, regardless of any value of potential difference ( V= 0 to ∞).
Eduvictors provides CBSE Previous Year Papers and Sample Question Papers for Class 10 Maths, Science, Social, English, Hindi and Sanskrit with/without solutions to help students in their board exam preparation.
1. Buy CBSE All In One Science Class 10 for 2021 Exam
Here attached the Science Sample Question Paper (2020-2021) along with Marking Scheme (published by CBSE).
Learning is a continual process. To improve scores, the best way is to learn and practice. Solving question papers help students to evaluate their knowledge and familarise with different types of question patterns being asked in examination.
Eduvictors provides CBSE Previous Year Papers and Sample Question Papers for Class Class 10 Maths, Science, Social, English, Hindi and Sanskrit with/without solutions to help students in their board exam preparation.
1. Buy Most Likely Question Bank - Science: CBSE Class 10 for 2021 Examination
Here attached the Science Sample Question Paper (2020-2021).
CBSE Class 10 Physics
Buy Oswal Science Question Bank (For 2021 Examination)
Directions: Read the question carefully and choose the right option from the choices given.
The first chapter of Chemistry talks about chemical reactions and equations. In a chemical reaction, reactants are transformed into products. In this series, the part-3 video discusses types of chemical reactions.
Following questions are covered:
Q1: What are the important types of chemical reactions.
Q2: What are combination reactions? Give examples.
Q3: Hydrogen burns in oxygen to form water. Identify the type of reaction.
CBSE Class 10 - Chemistry
Chapter: Acids and Bases
Q1: How is the strength of acid and base can be estimated?
Answer: Strength of acid and base can be estimated by using universal indicator.
Q2: What is a universal indicator?
Answer: Universal indicator is used to estimate the strength of an acid or a base. It is a mixture of several indicators. It shows different colours at different concentrations of H⁺ ions in the solution.
Q3: What is pH value of a solution?
Answer: The pH of a solution is inversely proportional to the concentration of hydrogen ions in it. Mathematically the pH of a solution is inversely proportional to the concentration of hydrogen ions in it. pH is a pure number, it has no units.
