Description : 2g of ferrous sulphate crystals are heated in a dry boiling tube. (i) List any two observations. (ii) Name the type of chemical reaction taking place. (iii) ‘Write the chemical equation for the reaction. -Chemistry
Last Answer : Answer. (i) •Green colour of Fe SO4 disappears and reddish brown solid is formed. • Smell of burning sulphur. (ii) Decomposition reaction
Description : Write balanced chemical equations for the following word equations: (a) Iron + Chlorine → Iron (III) chloride (b) Magnesium + dil sulphuric acid → Magnesium sulphate + water (c) Magnesium + oxygen → ... oxide (d) Calcium oxide + water → Calcium hydroxide (e) Sodium + chlorine → Sodium chloride
Last Answer : (a) Iron + Chlorine → Iron (III) chloride 4Fe + 3Cl2 → 2F2Cl3 (b) Magnesium + dil sulphuric acid → Magnesium sulphate + water 2Mg + 2H2SO4 → 2MgSO4 + 2H2 (c) Magnesium + oxygen → Magnesium oxide 2Mg ... hydroxide CaO + H2O → Ca(OH)2 (e) Sodium + chlorine → Sodium chloride 2Na + Cl2 → 2NaCl
Description : Write balanced equations for the reaction of: (i) aluminium when heated in air. Write the name of the product. (ii) iron with steam. Name the product obtained. (iii) calcium with water. Why does calcium start floating in water? -Chemistry
Last Answer : The bubbles of hydrogen stick to the surface of metal that is why it floats.
Description : State the type of chemical reactions and chemical equations that take place in the following: (i) Magnesium wire is burnt in air. (ii) Electric current is passed through water. (iii) Ammonia and hydrogen chloride gases’are mixed. -Chemistry
Last Answer : This is the Answer:
Description : Write balanced chemical equations for the following reactions: (a) Dilute sulphuric acid reacts with aluminium powder. (b) Dilute hydrochloric acid reacts with sodium carbonate. (c) Carbon dioxide is passed through lime water. -Chemistry
Last Answer : i hope it helped you
Description : (a) Write the essential condition for the following reaction to take place: 2AgBr--> 2Ag + Br2 Write one application of this reaction. (b) Complete the following chemical equation of a chemical ... science-5 (c) What happens when water is added to quick line. Write chemical equation. -Chemistry
Last Answer : Answer. This reaction is used in photography. (c) Slaked lime is formed with hissing sound and lot of heat is envolved.
Description : Which products will be obtained when lead nitrate is heated simply. Write balanced chemical equation for the reaction? State the type of chemical reaction that occur in the change. -Chemistry
Last Answer : Answer. Lead monoxide, nitrogen dioxide and oxygen gas will be liberated. It is thermal decomposition reaction.
Description : 10.(a) An ore on treatment with dilute hydrochloric acid produces brisk effervesces. What type of ore is this? What steps will be required to obtain metal from the enriched ore. , (b) ... in coin and colour of the solution ? Write balanced chemical equation of the reaction involved. -Chemistry
Last Answer : (a) Carbonate ore: (i) Calcination: Carbonate ore is heated in limited supply of air and oxide is obtained, e.g. (b) Copper, being more reactive than silver will displace silver from silver nitrate ... and there will be deposition of silver on copper coin. The colour of solution will turn to blue.
Description : The reagent used to distinguish iron(II) chloride and iron (ii) chloride (a)distilled water (b) NaOH (c) dil HCl (d) warm water
Last Answer : (b) NaOH
Description : (a) Write one example for each of decomposion reaction carried out with help of (i) Electricity (ii) Heat (iii) Light (b) Which of the following statements is correct and why copper can displace silver from silver nitrate and silver can displace copper from copper sulphate solution. -Chemistry
Last Answer : Thi is the Answer:
Description : Write a balanced chemical equation with state symbols for the following reactions : -Chemistry-10
Last Answer : (i) BaCl2 (aq) + Na2SO4 (aq) → BaSO4(s) + 2NaCl (aq) (ii) NaOH (aq) + HCl(aq) → NaCl(aq) + H2O(l)
Description : Write the balanced equation for the following chemical reactions. (i) Hydrogen + Chlorine → Hydrogen chloride (ii) Barium chloride + Aluminium sulphate → Barium sulphate + Aluminium chloride (iii) Sodium + Water → Sodium hydroxide + Hydrogen -Chemistry-10
Last Answer : (i) H2 + Cl2 → 2HCl (ii) 3 BaCl2 + Al2(SO4)3 → BaSO4 + 2 AlCl3 (iii) 2Na + 2H2O → 2NaOH + H2↑
Description : Give reason: a) Magnesium reacts more vigorously with hydrochloric acid than zinc or copper. b) Iron takes more time to react with dilute hydrochloric acid than magnesium and zinc
Last Answer : a) Magnesium reacts more vigorously with hydrochloric acid than zinc or copper. The reactivity of magnesium is higher than that of zinc. Hence it reacts with hydrochloric acid more vigorously. b) ... acid than magnesium and zinc As iron has lowest reactivity when compare to magnesium and zinc.
Description : Write balanced equation for the reaction between magnesium and hydrochloric acid. Name the product obtained, identify the type of reaction. -Chemistry
Last Answer : Answer. The product formed is magnesium chloride and hydrogen gas. It is a displacement reaction.
Description : Aquaregia is a mixture of the following in the ratio 1 : 3 by volume– (1) cone. HNO3 and cone. HCL (2) conc. HNO3 and conc. H2SO4 (3) dil. HCl and dil. HNO3 (4) cone. HCl and cone. HNO3
Last Answer : (3) dil. HCl and dil. HNO3 Explanation: Aqua regia or nitro-hydrochloric acid is a highly corrosive mixture of acids which is formed by freshly mixing concentrated Nitric acid (HNO3) and Hydrochloric acid (HCl), optimally in a volume ratio of 1:3. It is used in dissolving gold.
Description : Aquaregia is a mixture of the following in the ratio 1 : 3 by volume (1) conc. HNO3 and conc. HCl (2) conc. HNO3 and conc. H2 SO4 (3) dil. HCl and dil. HNO3 (4) conc. HCl and conc. HNO3
Last Answer : dil. HCl and dil. HNO3
Description : What information do you get from the following chemical equation: Zn(s) + 2HCl (dil) → ZnCl2 (aq) + H2(g)
Last Answer : This gives zinc chloride and hydrogen. The word equation is: Zinc + Hydrochloric acid → Zinc chloride + Hydrogen Formulae for the products are ZnCl2 and H2
Description : Gasification of the solid fuel converts its organic part into combustible by interaction with air/oxygen and steam so as to obtain a secondary gaseous fuel of high calorific value having no ash. Gasification reactions are ... __________ °C. (A) 400-500 (B) 900-1000 (C) 1400-1500 (D) 1700-1800
Last Answer : (B) 900-1000
Description : 1-Butyne reacts with (a) NaNH2 (b) Dil H2SO4 and HgSO4 (c) HBr (d) All of these
Last Answer : All of these
Description : .Identify the physical and chemical changes from the following (i)Burning of magnesium in air (ii)Electrolysis of water (iii)Tarnishing of silver spoon (iv)Sublimation of iodine -Chemistry
Last Answer : (i) Burning of magnesium in air : Chemical change (ii) Tarnishing of silver spoon : Chemical change (iii) Sublimation of iodine : Physical change (iv) Electrolysis of water to form hydrogen and oxygen is also a chemical change.
Description : Write the chemical equation of the reaction in which the following changes have taken place with an example of each: (i) Change in colour (ii) Change in temperature (iii) Formation of precipitate -Chemistry
Last Answer : (i)Cu (s) + 2AgNO3 (aq)———–> Cu(NO3)2(aq) + 2Ag The solution will become blue in colour and shiny silver metal will be deposited. (ii) NaOH + HCl ——&mdash ... )———–> Pbl2 (s) + 2KNO3 (aq) Yellow ppt Yellow precipitate of Pbl2will be formed.
Description : Write chemical reactions taking place in zone of reduction of blast furnace.
Last Answer : Write chemical reactions taking place in zone of reduction of blast furnace.
Description : You are given samples of three metals. Sodium, magnesium and copper. Suggest any two activities to arrange them in order of decreasing activity. -Chemistry
Last Answer : Activity 1: Sodium reacts with cold water vigorously to form sodium hydroxide and hydrogen gas Magnesium does not react with cold water but with hot water to form magnesium ! hydroxide and hydrogen gas. Hence sodium is more reactive than magnesium.
Description : The products formed in the reaction of cumene with `O_(2)` followed by treatment with dil. HCl are :
Last Answer : The products formed in the reaction of cumene with `O_(2)` followed by treatment with dil. HCl are : A. B. C. D.
Description : Amongst the compounds gives, the one that would form a brilliant colored dye on treatment with `NaNO_2` in dil. `HCl` followed by addition to an alkal
Last Answer : Amongst the compounds gives, the one that would form a brilliant colored dye on treatment with `NaNO_2` in dil. ... of `beta-`naphthol is A. B. C. D.
Description : How many anions evolve brownish gas when treated with dil. /con. HCl ? `(i) CO_(3)^(2-) " " (ii)SO_(3)^(2-) " " (iii) NO_(2)^(-) " " (iv)Cl^(-)` `(v)
Last Answer : How many anions evolve brownish gas when treated with dil. /con. HCl ? `(i) CO_(3)^(2-) " " (ii)SO_(3)^(2-) ... NO_(3)^(-) " " (vii) CH_(3)CO O^(-)`
Description : Find the total number of acidic radical which produce volatile product with dil HCl : `(i) SO_(4)^(2-) " " (ii) I^(-) " " (iii) NO_(2)^(-) " " (iv) NO
Last Answer : Find the total number of acidic radical which produce volatile product with dil HCl : `(i) SO_(4)^(2-) " " (ii) ... SO_(3)^(2-) " " (vi) HCO_(3)^(-)`
Description : Number of ions which are identified by dil. HCl from the following. `(i) SO_(4)^(2-) " " (ii) CO_(3)^(2-) " " (iii) SO_(3)^(2-) " " (iv) HCO_(3)^(-)`
Last Answer : Number of ions which are identified by dil. HCl from the following. `(i) SO_(4)^(2-) " " (ii) CO_(3)^(2-) " ... CH_(3)CO O^(-) " " (viii) PO_(4)^(3-)`
Description : Which of the following anions are identified by dil. HCl :
Last Answer : Which of the following anions are identified by dil. HCl : A. `NO_(2)^(-),NO_(3)^(-),CO_(3)^(2-)` B. `NO_(2) ... D. `CH_(3)CO O^(-),I^(-),CO_(3)^(2-)`
Description : Alkaloids are usually purified by extraction with (A) Ether (B) Dil HCl (C) NaOH (D) Chloroform
Last Answer : Answer : B
Description : Write the molecular formulae of: 1. Copper oxide 2. Iron (III) chloride 3. Sodium hydroxide 4. Iron (II) sulphide 5. Lead (II) oxide 6. Hydrogen nitrate (nitric ... Hydrogen sulphate (sulphuric acid) 8. Calcium hydroxide 9. Magnesium carbonate 10.Ammonium carbonate
Last Answer : 1. Copper oxide - CuO 2. Iron (III) chloride - FeCl3 3. Sodium hydroxide - NaOH 4. Iron (II) sulphide - FeS 5. Lead (II) oxide - PbO 6. Hydrogen nitrate (nitric acid) - HNO3 7. ... ) - H2SO4 8. Calcium hydroxide - Ca(OH)2 9. Magnesium carbonate - MgCO3 10.Ammonium carbonate - (NH4)2CO3
Description : Why does the colour of copper sulphate solution change when an iron nail is dipped in it? Write two observations. -Chemistry
Last Answer : Answer. It is because displacement reaction takes place. Iron displaces copper from copper sulphate solution and forms pale green coloured solution of FeS04 and reddish brown copper metal gets deposited. Fe(s) + CuS04(aq) ——–> FeS04(aq) + Cu(s)
Description : Two half-reactions of an electrochemical cell are given below : MnO-4 (aq) + 8H+ (aq) + 5e- → Mn2+ (aq) + 4H2O (I), E° = 1.51 V Sn2+ (aq) → Sn4+ (aq) + 2e- ... the redox equation from the standard potential of the cell and predict if the reaction is reactant favoured or product favoured. -Chemistry
Last Answer : The reactions can be represented at anode and at cathode in the following ways : At anode (oxidation) : Sn2+ → = Sn4+ (aq) + 2e- ] 5 E° = + 0.15 V At cathode (reduction) : MnO-4(aq) + 8H+ ... = E°cathode - E°anode = 1.51 - 0.15 = + 1.36 V ∴ Positive value of E°cell favours formation of product.
Description : Two half-reactions of an electrochemical cell are given below : MnO-4 (aq) + 8H+ (aq) + 5e- → Mn2+ (aq) + 4H2O (I), E° = 1.51 V Sn2+ (aq) → Sn4+ (aq) + ... -reactions and calculate the cell potential from the standard potentials and predict if the reaction is reactant or product favoured. -Chemistry
Last Answer : The reactions can be represented at anode and at cathode in the following ways : At anode (oxidation) : Sn2+ → Sn4+ (aq) + 2e- ] 5 E° = + 0.15 V Af cathode (reduction) : MnO-4(aq) + 8H+ ( ... = E°cathode - E°anode = 1.51 - 0.15 = + 1.36 V ∴ Positive value of E°cell favours formation of product.
Description : A Unknown salt (S) when heated with dil `H_(2)SO_(4)` does not evolve brown vapours but with conc. `H_(2)SO_(4)` brown vapours are obtained. The vapou
Last Answer : A Unknown salt (S) when heated with dil `H_(2)SO_(4)` does not evolve brown vapours but with conc. `H_(2)SO_(4)` ... 3)^(-)` C. `I^(-)` D. `Br^(-)`
Description : What is observed when a solution of potassium iodide solution is added to a solution of lead nitrate? Name the type of reaction. Write a balanced chemical equation to represent the above chemical reaction. -Chemistry
Last Answer : Answer.Yellow precipitate of lead iodide is formed. It is precipitation reaction. Pb( NO3)2 (aq) + 2KI (aq) —-> Pbl2 (s) + 2KNO3 (aq) It is also called double displacement reaction.
Description : (a) Define a balanced chemical equation. Why should an equation be balanced? (b) Write the balanced chemical equation for the following reaction: (i) Phosphorus burns in presence of chlorine to form phosphorus penta chloride. (ii) Burning of natural gas. (iii) The process of respiration. -Chemistry
Last Answer : Answer. (a) Balanced chemical equation has an equal number of atoms of different elements in the reactants and products. According to law of conservation of mass, matter can neither be created nor be destroyed in a chemical ... C6H12O6 (s) + 6O2 (g) + 6H2O ---> 6CO2 (aq) + 12H2O (l) + energy
Description : i) Write a balanced chemical equation for process of photosynthesis. (ii)When do desert plants take up carbon dioxide and perform photosynthesis? -Chemistry
Last Answer : Answer. (ii) In desert plants the stomata are open at night. They take CO2 at night and is stored in the form of acid and is used during day time for photosynthesis.
Description : Explain why calcium metal after reacting with water starts floating on its * surface. Write the chemical equation for the reaction. Name one more metal that starts floating after some time when immersed in water. -Chemistry
Last Answer : Calcium starts floating because the bubbles of hydrogen gas formed stick to the surface of metal. Magnesium reacts with hot water and starts floating due to the bubbles of hydrogen gas sticking to its surface.
Description : (2) brown bottles stops the passage of light through it Explanation: Silver Nitrate is stored in dark bottles in a laboratory to prevent chemical reactions as it is sensitive to light. It reacts to light to produce silver metal.
Last Answer : In upper layer of atmosphere ozone is formed by - (1) the action of ultraviolet rays on oxygen (2) the combination of oxygen molecules (3) subjecting oxygen to high pressure (4) the action of nitrogen on oxygen in atmosphere
Description : Define the term valency. What is the valency for magnesium and copper? -Chemistry 9th
Last Answer : The no.of electrons required for the element to be octate or duplate is known as valency. Magnesium = 2 Copper = 1 hope this helps u
Description : (3) preventing rapid setting of cement Explanation: Portland cement clinker is a hydraulic material which shall consist of at least two-thirds by mass of calcium silicates, the remainder consisting of ... mixed with water by way of a complex series of chemical reactions still only partly understood.
Last Answer : Milk is a colloidal system in which: (1) Water is dispersed in fat (2) Fat is dispersed in water (3) Fat and water are dispersed in each other (4) Fat is dissolved
Description : The chemistry of corrosion of iron is essentially an electrochemical phenomenon. Explain the reactions occurring during the corrosion of iron in the atmosphere. -Chemistry
Last Answer : The mechanism of corrosion is explained on the basis of electrochemical theory. By taking example of rusting of iron, we Refer tothe formation of small electrochemical cells on the surface of iron. The redox reaction involves ... net resultant Redox reaction is 2Fe(s) + O2 (g) + 4H+ → 2Fe2+ + 2H2O
Description : Give reasons for the following observations: (a) The element carbon forms a very large number of compounds. (b) Air holes of a gas burner have to be adjusted when the heated vessels get blackened by the flame. (c) Use of synthetic detergents causes pollution of water. -Chemistry
Last Answer : Answer. (a) Carbon forms large number of compounds since carbon is small in size and can form stable covalent bonds (catenation) and it shows tetravalency. (b) Air holes of gas burner are ... not get blackened. (c) Some synthetic detergents are non-biodegradable, therefore, cause pollution of water.
Description : In which of the branches of chemistry would the development of a theory about how a reaction takes place best be carried o w) analytical x) inorganic y) organic z) physical
Last Answer : ANSWER: Z -- PHYSICAL
Description : A compound X' on heating with excess conc. sulphuric acid at 443 K gives an unsaturated compound Y'. X' also reacts with sodium metal to evolve a colourless gas Z'. Identify X', Y' ... the chemical reaction of formation of Y' and also write the role of sulphuric acid in the reaction. -Science
Last Answer : X-Ethanol/ (C2H5OH)/Ethyl AlcoholY- Ethene / (C2H4)Z- Hydrogen/ (H2)Role of sulphuric acid - dehydrating agent
Description : Pyridine reacts with HCl to form (a) Pyridinium chloride (b) 2-Chloropyridine (c) 3-Chloropyridine (d) All of these
Last Answer : Pyridinium chloride
Description : Predict which of the following alkenes reacts the fastest with HCl? (a) CH3CH2CH2CH2CH=CH2 (b) cis-CH3CH2CH=CHCH2CH3 (c) trans-CH3CH2CH=CHCH2CH3 (d) (CH3)2C=CHCH2CH3
Last Answer : (CH3)2C=CHCH2CH3
Description : Galvanization of iron is carried out using (1) Zinc (2) Tin (3) Copper (4) Chromium
Last Answer : Zinc
Description : What happens when ethanol is heated with acidified potassium dichromate solution? Write the chemical equation.
Last Answer : Answer. Ethanol is oxidised to ethanoic acid with the help of acidified K2Cr2O7. CH3CH2OH + 2O → CH3COOH + H2O