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Class 10 · Science · Medium
→When water is added to calcium oxide, the container becomes hot. Which conclusion is correct from this observation?
Class 10 · Science · Medium
→If two reactants combine to form only one product and heat is released, what is the correct classification of the reaction?
Class 10 · Science · Medium
→A student burnt a magnesium ribbon in air and obtained a white powder. Which is the correct conclusion about the powder and the reaction?
Class 10 · Science · Medium
→In an unknown reaction, an insoluble white solid forms, but no noticeable temperature change is observed. What is the most appropriate conclusion?
Class 10 · Science · Medium
→Which statement best identifies a chemical reaction?
Class 10 · Science · Medium
→If the total mass in a closed container after a chemical reaction remains equal to the total mass before the reaction, which law does this illustrate?
Class 10 · Science · Medium
→Which of the following examples involves a change in properties and the formation of a new substance?
Class 10 · Science · Medium
→A student adds zinc granules to a blue copper sulfate solution. After some time, the blue colour fades and a reddish-brown coating appears on the zinc. Which conclusion is correct?
Class 10 · Science · Medium
→A student did not clean a magnesium ribbon before burning it, so it appeared to burn slowly. What is the main purpose of cleaning the ribbon?
Class 10 · Science · Medium
→Which of the following is only a physical change?
Class 10 · Science · Medium
→When is a downward arrow used in a chemical equation?
Class 10 · Science · Easy
→When can an upward arrow be used in a chemical equation?
Class 10 · Science · Easy
→What is the correct meaning of the state symbol (aq) in a chemical equation?
Class 10 · Science · Medium
→If a substance appears to change colour but no other clear sign of a chemical change is observed, what should be done?
Class 10 · Science · Medium
→If bubbles form in an experiment, which conclusion is most careful?
Class 10 · Science · Medium
→Which observation indicates that a reaction is endothermic?
Class 10 · Science · Medium
→Which observation shows that a chemical reaction is exothermic?
Class 10 · Science · Medium
→What is done to convert a skeletal chemical equation into a balanced chemical equation?
Class 10 · Science · Medium
→Why should subscripts in chemical formulae not be changed while balancing a chemical equation?
Class 10 · Science · Medium
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