You are provided with some compounds in the box.
| PbO | CH4 | PbO2 | CO2 | HCl | NCl3 | SO2 |
Choose the most appropriate compound which fits the descriptions (a) to (c) given below:
(a) A colourless gas which turns acidified K2Cr2O7 from orange to green.
(b) A yellow explosive oily liquid formed when excess chlorine gas reacts with ammonia gas.
(c) A yellow metallic oxide formed on thermal decomposition of PbCO3.
(a) SO2
Explanation – Sulphur dioxide is a colourless gas. It is a reducing agent and turns acidified potassium dichromate solution from orange to green.
(b) NCl3
Explanation – Nitrogen trichloride is a yellow explosive oily liquid formed when excess chlorine reacts with ammonia.
\mathrm{NH_3 + 3Cl_2 \rightarrow NCl_3 + 3HCl}(c) PbO
Explanation – Lead(II) oxide is yellow and is produced when lead carbonate (PbCO3) undergoes thermal decomposition.
\mathrm{PbCO_3 \xrightarrow{\Delta} PbO + CO_2}More ICSE Moderate level questions
Give one significant observation when: (a) Barium chloride solution is added to zinc sulphate solution. (b) Lead nitrate is heated strongly. (c) Chlorine gas is passed through moist starch iodide paper.
Give one relevant observation for the following: (a) Sodium hydroxide is added dropwise to Calcium nitrate solution. (b) Dilute Hydrochloric acid is added to Iron (II) sulphide. (c) An amphoteric metal is added to hot concentrated alkali.
Choose the substances given in the box below to answer the following questions: Iron Magnesium sulphite Zinc Sodium sulphide Lead Ferric chloride Copper Ferrous sulphate (a) The metal that will not produce hydrogen gas when reacted with dilute acids. (b) The compound that will produce sulphur dioxide gas when reacted with dilute HCl. (c) The solution of this compound produces dirty green precipitate with NaOH.
Rita added dilute hydrochloric acid to four metals. She recorded her observations in the table given below. While noting her observations she made some errors. Metals Observations 1 copper a gas was given off 2 iron a gas was given off 3 magnesium no gas was given off 4 zinc a gas was given off Which observation(s) made by Rita is/are correct? (a) 1 only (b) 3 only (c) Both 1 and 4 (d) Both 2 and 4
Given below are organic compounds labelled A to F. Answer the questions that follow: (a) Which compound forms a single product with bromine? (b) Which two compounds have the same molecular formula? (c) Which two compounds will react together in the presence of concentrated H2SO4 to form a product with a fruity smell?
Study the table given below. Use only the letters given in the table to answer the questions. Do not identify the elements. IA IIA IIIA IVA VA VIA VIIA 0 E J Q L G M D P N (a) State the valency of element ‘G’. (b) Which element can exhibit catenation? (c) Write the formula of the compound formed between ‘M’ and ‘P’.
Rohit took two different salt solutions in test tubes C and D as shown in the figure below. He added dilute HCl to each of the two test tubes. The products formed in the test tubes C and D are silver chloride and lead chloride respectively. State: (a) one common observation made by Rohit in both the reactions. (b) the observations made by him on addition of excess of ammonium hydroxide to the products formed in: 1. test tube C 2. test tube D
Draw the dot and cross structure of the following: (a) An ionic compound formed when Mg reacts with the dilute HCl. (b) A covalent compound formed when H2 reacts with Cl2. (c) The positive ion produced when ammonia gas is dissolved in water. [ Atomic number: Mg = 12, Cl = 17, H = 1, N = 7 ]
Acidulated water is electrolysed using platinum electrodes. Answer the following questions: (a) Why is dilute sulphuric acid added to water? (b) Write the reaction taking place at the cathode. (c) What is the observation at the anode?
P, Q, R and S are the different methods of preparation of salts. P – Simple displacement Q – Neutralisation by titration R – Precipitation S – Direct combination Choose the most appropriate method to prepare the following salts: (a) PbCl2 (b) FeCl3 (c) Na2SO4
Given below is a diagram showing the placement of five different oxides. With respect to the given diagram answer the following questions: (a) Name the type of oxide represented in region X in the diagram. (b) Identify the oxide which has been incorrectly placed in the above diagram. (c) Name the oxide from the above diagram which will form an alkali when dissolved in water.
Give balanced equations for the following: (a) Action of dilute hydrochloric acid on ammonium carbonate. (b) Oxidation of sulphur with hot concentrated nitric acid. (c) Reaction of concentrated sulphuric acid with carbon.
