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Class 10 · Science · Expert
→Why do foods containing oils and fats remain unspoiled for longer when packed in nitrogen-filled packets?
Class 10 · Science · Expert
→Why can ghee kept in warm open air spoil quickly?
Class 10 · Science · Medium
→Which main chemical reaction causes the change in taste and smell during rancidity of oils and fats?
Class 10 · Science · Expert
→Which of the following equation represents a reaction that is both a combination reaction and an exothermic reaction?
Class 10 · Science · Expert
→Why can rusting begin when a painted iron surface is scratched?
Class 10 · Science · Easy
→Which condition will be most helpful for rusting of iron?
Class 10 · Science · Easy
→Removal of hydrogen and addition of hydrogen are associated with which processes, respectively?
Class 10 · Science · Expert
→Which statement about oxidation and reduction is correct?
Class 10 · Science · Easy
→In the same reaction, one substance loses oxygen and another gains oxygen. What is it called?
Class 10 · Science · Medium
→In the reaction CuO + H₂ → Cu + H₂O, water is formed. What does this show about hydrogen?
Class 10 · Science · Expert
→When black copper(II) oxide is heated with hydrogen gas, it changes into reddish-brown copper. This change is primarily evidence of which process?
Class 10 · Science · Expert
→Which symbol is used in a chemical equation to show the formation of an insoluble solid in a precipitation reaction?
Class 10 · Science · Expert
→In the reaction \(\mathrm{CuO + H_2 \rightarrow Cu + H_2O}\), which substance is reduced?
Class 10 · Science · Expert
→Which of the following reactions involves oxidation of one substance and reduction of another substance simultaneously?
Class 10 · Science · Expert
→A student wrote \(\mathrm{Fe + H_2O \rightarrow FeO + H_2}\) for the reaction of iron with steam. What is the main error in this equation?
Class 10 · Science · Easy
→Metal A displaces metal B from its salt, and metal B does not displace metal A. What is the correct conclusion?
Class 10 · Science · Medium
→Which reaction is an example of a double displacement reaction in which a precipitate is formed?
Class 10 · Science · Medium
→When an iron nail is placed in copper sulphate solution, a reddish-brown coating forms on the nail and the solution turns green. What is the correct reason?
Class 10 · Science · Easy
→What is the main difference between electrolytic decomposition and thermal decomposition?
Class 10 · Science · Expert
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