NCERT
- Why is respiration considered an exothermic reaction? Explain. Respiration is considered as an exothermic reaction because in respiration oxidation of glucose takes place which produces large amount of h... 1
- What does one mean by exothermic and endothermic reactions? Give examples. Exothermic reaction:: Reactions in which heat is released along with the formation of products are called exothermic chemical reactions. Eg:... 1
- Write the balanced chemical equation for the following and identify the type of reaction in each case. (a) 2KBr (aq) + BaI₂ (aq) → 2KI (aq) + BaBr₂ (s): Double displacement reaction (b) ZnCO₃ (s) → ZnO (s) + CO₂ (g): Decomposition reaction (c)... 1
- Write the balanced chemical equations for the following reactions. (a) Calcium hydroxide (a) Ca(OH)₂ + CO₂ → CaCO₃ + H₂O (b) Zn + 2AgNO₃ → Zn(NO₃)₂ + 2Ag (c) 2Al + 3CuCl₂ → 2AlCl₃ + 3Cu (d) BaCl2 + K₂SO₄ → BaSO₄ + 2KCl 1
- Balance the following chemical equations. (i) HNO3 + Ca(OH)2 → Ca(NO3)2 + H2O (i) 2HNO₃ + Ca(OH)₂ → Ca(NO₃)₂ + 2H₂O (ii) 2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O (iii) NaCl + AgNO₃ → AgCl + NaNO₃ (iv) BaCl₂ + H₂SO₄ → BaSO₄ + 2HCl 1
- Translate the following statements into chemical equations and then balance them. (a) 3H₂ (g) + N₂ (g) → 2NH₃ (g) (b) 2H₂S (g) + 3O₂ (g) → 2H₂O (l) + 2SO₂ (g) (c) 3BaCl₂ (aq) + Al₂(SO₄)₃ (aq) → 2AlCl₃ (aq) + 3BaSO₄ (s) (d)... 1
- What is a balanced chemical equation? Why should chemical equations be balanced? A reaction which has an equal number of atoms of all the elements on both sides of the chemical equation is called a balanced chemical equat... 1
- What happens when dilute hydrochloric acid is added to iron filings? Tick the correct answer. Correct option is a) Hydrogen gas and iron chloride are produced. 1
- Fe2O3 + 2Al → Al2O3 + 2Fe The above reaction is an example of a Correct option is d) displacement reaction. 2
- Which of the statements about the reaction below are incorrect? 2PbO (s) + C (s) → 2Pb (s) + CO2 (g) Correct option is (i) (a) and (b) 2
- Identify the substances that are oxidised and the substances that are reduced in the following (i) Sodium (Na) is oxidised as it gains oxygen and oxygen gets reduced. (ii) Copper oxide (CuO) is reduced to copper (Cu) while hydrogen (H₂... 1
- Give an example of a double displacement reaction other than the one given in Activity 1.10. Sodium carbonate reacts with calcium chloride to form calcium carbonate and sodium chloride. Na₂CO₃+CaCl₂→ CaCO₃+2NaCl In this reaction, sod... 1
- Why does the colour of copper sulphate solution change when an iron nail is dipped in it? When an iron nail dipped in the copper sulphate solution than iron displaces copper from the copper sulphate because iron is more reactive t... 1
- Why is the amount of gas collected in one of the test tubes in Activity 1.7 double Water contains two parts of hydrogen and one part oxygen. Therefore, during the electrolysis of water the amount of hydrogen gas collected i... 1
- A solution of a substance ‘X’ is used for white washing. (i) The substance 'X' is calcium oxide. Its chemical formula is CaO. (ii) Calcium oxide reacts vigorously with water to form calcium hydroxi... 1
- Write the reaction of the substance ‘X’ named in (i) above with water. Calcium oxide reacts vigorously with water to form calcium hydroxide (slaked lime). CaO (s) + H₂O (l) → Ca(OH)₂ (aq) Calcium Oxide (Quick Li... 2
- (i) Name the substance ‘X’ and write its formula. The substance 'X' is calcium oxide. Its chemical formula is CaO. 1
- Sodium hydroxide solution (in water) reacts with hydrochloric acid solution (in water) (ii) NaOH (aq) + HCl (aq) → NaCL (aq) + H₂O (l) 2
- Solutions of barium chloride and sodium sulphate in water react to give insoluble barium (i) BaCl₂ (aq) + Na₂SO₄ (aq) → BaSO₄ (s) + 2NaCl (aq) 2
- Write the balanced equation for the following chemical reactions. (i) H₂ (g) + Cl₂ (g) → 2HCl (g) (ii) 3BaCl₂ (s) + Al₂(SO₄)₃ (s) → 3BaSO₄ (s) + 2AlCl₃ (s) (iii) 2Na(s) + 2H₂O (l) → 2NaOH (aq) + H₂ (g) 1
- Why should a magnesium ribbon be cleaned before it is burnt in air? Magnesium is a very reactive metal. When stored, it reacts with oxygen to form a layer of magnesium oxide on its surface. This layer of magn... 1
- Computer Application solutions CBSE std 10th frankedu.com You can get all solutions on frankedu website Link-> https://www.frankedu.com/studentzonebook/1557119001-0llComputer%20Applications%20CBSE%2... 1
- The philosophy being followed by S and M is not followed by most other Correct option is (a) Optional 2
- As “The decision making authority is pushed down the chain of command” at S and M enterprises, Correct option is (a) There is no requirement for approval from many levels 1