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Class 10 · Science
→A student heated 12.0 g of calcium carbonate in an open crucible and obtained 6.7 g of solid. Which evaluation is correct?
Class 10 · Science
→How are products predicted in a double displacement reaction?
Class 10 · Science
→Why does a precipitate form when aqueous barium chloride reacts with aqueous sodium sulphate?
Class 10 · Science
→When two aqueous solutions are mixed, white insoluble barium sulphate and sodium chloride are formed. Which pair of original solutions could have been used?
Class 10 · Science
→Metal A displaces metal B and metal B displaces metal C from their salt solutions. Which is least reactive?
Class 10 · Science
→Zinc displaces copper from an aqueous solution of its salt, but copper does not displace zinc from an aqueous solution of its salt. What is the most correct conclusion?
Class 10 · Science
→In the thermite reaction \(Fe_2O_3 + 2Al \rightarrow Al_2O_3 + 2Fe\), which substance acts as the reducing agent?
Class 10 · Science
→When an iron nail is placed in copper sulphate solution, which substance is deposited on the surface of the nail?
Class 10 · Science
→Which problem is solved by adding a small amount of acid during electrolysis of water?
Class 10 · Science
→Which correctly identifies oxidation and reduction in the following reaction? \(\mathrm{Zn + CuSO_4 \rightarrow ZnSO_4 + Cu}\)
Class 10 · Science
→During electrolysis of water, at the same temperature and pressure, if the volume of oxygen collected is 7 mL, what volume of hydrogen will be collected?
Class 10 · Science
→What is the scientific reason for storing silver bromide in a dark-coloured bottle?
Class 10 · Science
→When silver chloride is exposed to sunlight, it turns grey. What is the main reason for this colour change?
Class 10 · Science
→Why is it incorrect to identify the brown fumes evolved on heating lead nitrate as oxygen?
Class 10 · Science
→When lead nitrate is heated, a solid residue and a brown gas are formed. Which pair is correct?
Class 10 · Science
→In the reaction \(CuO + H_2 \rightarrow Cu + H_2O\), which statement about oxidation and reduction is correct?
Class 10 · Science
→When water is added to calcium oxide, calcium hydroxide is formed and heat is released. What type of reaction is this?
Class 10 · Science
→When a single compound breaks down into two or more simpler substances on heating, what type of reaction is it?
Class 10 · Science
→In the reaction of magnesium with oxygen, if 2 formula units of magnesium oxide are formed, how many \(\mathrm{O_2}\) molecules are needed to balance the equation?
Class 10 · Science
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