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You are Sanjeet of 122, Arjun Nagar, New Delhi. A number of scooters and cars are parked in your locality without any order, causing blockage of the streets. Write a letter to the local Secretary of the Resident’s Association complaining against this problem.

Study the graph given below. The chart depicts the number of students of class tenth speaking English and Hindi in three different types of schools in New Delhi. Based on the details given in the bar-graph given below, write an analytical paragraph in 100-120 words.

11 amazing facts about chemistry.

KVPY 2020 : Answer Keys Released, Raise Objections By Feb 15

CBSE 10th,12th Board Exam 2021 : Board Exam Time Table Released

CBSE BOARD EXAM 2021 : Covid-19 Guidelines By CBSE And Mandatory Protocols

What is a balanced chemical equation ? Why should chemical equations be balanced ?

What happens when dilute hydrochloric acid is added to iron filings ? Tick the correct answer :(a) Hydrogen gas and iron chloride are produced.(b) Chlorine gas and iron hydroxide are produced.(c) No reaction takes place.(d) Iron salt and water are produced.

Fe2O3 + 2Al → Al2O3 + 2FeThe above reaction is an example of a(a) combination reaction(b) double displacement reaction(c) decomposition reaction(d) displacement reaction

Identify the substances that are oxidised and the substances which are reduced in the following reactions.(i) 4Na(s) + O2(g) → 2Na2O(s)(ii) CuO (s) + H2(g) → Cu (s) + H2O(l)

Why does the colour of copper sulphate solution change when an iron nail is dipped in it ?

Why is the amount of gas collected in one of the test tubes in text book Activity 1.7 (i.e., electrolysis of water) double of the amount collected in the other? Name this gas.

A solution of a substance ‘X’ is used for white washing.(i) Name the substance ‘X’ and write its formula.(ii) Write the reaction of the substance ‘X’ named in (i) above with water.

Write a balanced chemical equation with state symbols for the following reactions :(i) Solutions of barium chloride and sodium sulphate in water react to give insoluble barium sulphate and the solution of sodium chloride.(ii) Sodium hydroxide solution (in water) reacts with hydrochloric acid solution (in water) to produce sodium chloride solution and water.

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

Why should a magnesium ribbon be cleaned before burning in air ?