Muft Shiksha
Update

Muft Shiksha™ एक 100% Free Education Portal है 🇮🇳, जिसका उद्देश्य Class 9–12 के हर विद्यार्थी तक High-Quality Education को पूरी तरह मुफ्त पहुँचाना है। 🇮🇳 हम मानते हैं कि अच्छी शिक्षा किसी student की आर्थिक स्थिति पर निर्भर नहीं होनी चाहिए। 🇮🇳 हर विद्यार्थी को वही Quality Study Material, MCQs, Quizzes, Exam Preparation, Concept-Based Learning और Bilingual Support मिलना चाहिए, जो आमतौर पर महंगी Coaching या Premium Platforms में मिलता है। Muft Shiksha™ 🇮🇳 इसी सोच के साथ बनाया गया है

Subjects

Science

Chemical Reactions and Equations

रासायनिक अभिक्रियाएँ और समीकरण

In Class 10 Science, under the chapter Chemical Substances – Nature and Behaviour, this topic introduces chemical reactions as changes that form new substances. Students learn to identify reactants and products, represent reactions through word and chemical equations, and write balanced equations using correct chemical formulae while following the law of conservation of mass.

Practice questions

Which statement best explains the relationship between a balanced chemical equation and the law of conservation of mass?When water is added to calcium oxide, calcium hydroxide is formed and the container becomes hot. Which two types of reaction does this represent?The gas produced on heating calcium carbonate is passed through lime water. The milkiness of lime water is caused by the formation of which substance?What is the role of heat in thermal decomposition of calcium carbonate?When lead nitrate is heated, a brown gas evolves and a solid residue remains. Which explanation is correct?On heating lead nitrate, the evolution of a brown gas confirms the formation of which gas?White silver chloride turns grey in sunlight. What type of reaction occurs, and which product causes the grey colour?What is the deeper reason for keeping silver bromide in a dark coloured bottle?Which of the following equations represents an exothermic combination reaction?What is the main purpose of adding a few drops of dilute sulphuric acid during the electrolysis of water?In the electrolysis of water, if the volume of oxygen is five millilitres, what is the expected volume of hydrogen?When an iron nail is placed in a blue copper sulphate solution, a reddish-brown copper coating forms on the nail and the solution turns pale green. What causes both changes?When an iron nail is placed in copper sulphate solution, a decrease in the concentration of which ion causes the blue colour of the solution to fade?Metal A displaces metal B from a solution of its salt, and metal B displaces metal C from a solution of its salt. What is the correct order of reactivity of the metals?Zinc displaces copper from copper sulphate solution, but copper does not displace zinc from zinc sulphate solution. What is the correct conclusion?When two aqueous solutions are mixed, a white precipitate of barium sulphate forms and sodium chloride remains in solution. Which pair of reactants is correct?When a precipitation reaction occurs on mixing two aqueous solutions, what is its clearest visible evidence?Why is the reaction between barium chloride and sodium sulphate classified as both a double-displacement and a precipitation reaction?If copper oxide becomes copper in the reaction with hydrogen, what change has occurred?A student writes the reaction for heating potassium chlorate as \(KClO_3 \xrightarrow{\Delta,\,MnO_2} KCl + O_2\). What is the correct evaluation of this equation?