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Class 10 · Science
→If heat is written on the products side of a chemical equation, what type of reaction does it represent?
Class 10 · Science
→A student wrote the thermal decomposition of lead nitrate as Pb(NO₃)₂ → PbO + NO₂ + O₂ and claimed that it was balanced. Which change gives the correct balanced equation?
Class 10 · Science
→Which statement is correct for the reaction \\(CuO + H_2 \rightarrow Cu + H_2O\\)?
Class 10 · Science
→In a nitrogen-filled packet, how are the oils in chips mainly prevented from becoming rancid?
Class 10 · Science
→A student heated copper powder in air. The reddish-brown copper turned black. Which statement about this change is correct?
Class 10 · Science
→What is the main chemical process behind bad taste and smell of oils and fats?
Class 10 · Science
→Why can iron remain protected from rusting for some time even if the zinc coating in galvanisation is scratched?
Class 10 · Science
→A student places a clean zinc strip in a blue copper sulphate solution. After some time, a reddish-brown coating forms on the strip and the blue colour of the solution fades. Which is the correct explanation of this observation?
Class 10 · Science
→Which environment is most favourable for rusting of iron?
Class 10 · Science
→Which of the following reaction is an example of an exothermic displacement reaction?
Class 10 · Science
→In the reaction (2 ext{Al}+3 ext{CuCl}_2 ightarrow2 ext{AlCl}_3+3 ext{Cu} ), a student says that 1 mol of aluminium will produce 1 mol of copper. Which statement correctly corrects the error?
Class 10 · Science
→If substance A loses oxygen and substance B gains that oxygen, what is the correct sequence of changes in substances A and B?
Class 10 · Science
→In which of the following reactions does the same element undergo both oxidation and reduction simultaneously?
Class 10 · Science
→When copper(II) oxide is heated with hydrogen, copper is formed. Which process occurs to copper(II) oxide in this reaction?
Class 10 · Science
→Which statement correctly describes oxidation and reduction in the reaction \\(\mathrm{CuO + H_2 \rightarrow Cu + H_2O}\\)?
Class 10 · Science
→Which of the following equations represents a displacement reaction in which oxidation and reduction occur simultaneously?
Class 10 · Science
→Two aqueous solutions are mixed and a white insoluble solid and sodium chloride are formed. What could be the original solutions?
Class 10 · Science
→Metal A displaces metal B from a solution of its salt, and metal B displaces metal C from a solution of its salt. Which metal is the least reactive?
Class 10 · Science
→In the reaction \(\mathrm{CuO + H_2 \rightarrow Cu + H_2O}\), which reactant is the reducing agent?
Class 10 · Science
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