(a) Mercury (a metal) is a liquid at room temperature' Bromine (a non-metal) is a liquid at room temperature' (b) Sodium (a metal) is very soft. Diamond (a form of carbon) is very hard. (c) Gallium has a very low melting point' Diamond (a non-metal) has a very high melting point.
(a) Mercury (a metal) is a liquid at room temperature’
Bromine (a non-metal) is a liquid at room temperature’
(b) Sodium (a metal) is very soft.
Diamond (a form of carbon) is very hard.
(c) Gallium has a very low melting point’
Diamond (a non-metal) has a very high melting point.
(a) Copper is higher than silver in the activity series of metals. It displaces silver from silver nitrate and forms copper nitrate which gives a bluish green colour in the solution. (b) Cu(s) + 2AgNO₃ (aq) ⟶ Cu(NO₃)₂ (aq) + 2Ag (s)
(a) Copper is higher than silver in the activity series of metals. It displaces silver from silver nitrate and forms copper nitrate which gives a bluish green colour in the solution.
(b) Cu(s) + 2AgNO₃ (aq) ⟶ Cu(NO₃)₂ (aq) + 2Ag (s)
Change in smell and taste of fats and oils containing food due to atmospheric oxidation is called rancidity. Methods to prevent rancidity : (i) Keep such foods in air tight containers' (ii) Flush bags of such foods like chips with an inert gas nitrogen.
Change in smell and taste of fats and oils containing food due to atmospheric oxidation is called rancidity.
Methods to prevent rancidity :
(i) Keep such foods in air tight containers’
(ii) Flush bags of such foods like chips with an inert gas nitrogen.
Write one example of each of the following: (a) A metal and a non-metal which are liquids at room temperature. (b) A metal which is very soft and a non-metal which is very hard. (c) A metal which has very low melting point and a non-metal which has very high melting point.
(a) Mercury (a metal) is a liquid at room temperature' Bromine (a non-metal) is a liquid at room temperature' (b) Sodium (a metal) is very soft. Diamond (a form of carbon) is very hard. (c) Gallium has a very low melting point' Diamond (a non-metal) has a very high melting point.
(a) Mercury (a metal) is a liquid at room temperature’
See lessBromine (a non-metal) is a liquid at room temperature’
(b) Sodium (a metal) is very soft.
Diamond (a form of carbon) is very hard.
(c) Gallium has a very low melting point’
Diamond (a non-metal) has a very high melting point.
When a copper wire is left in silver nitrate solution, it is observed that the solution turns bluish green. (a) Explain the observation. (b) Write the balanced chemical equation to represent the change taking place.
(a) Copper is higher than silver in the activity series of metals. It displaces silver from silver nitrate and forms copper nitrate which gives a bluish green colour in the solution. (b) Cu(s) + 2AgNO₃ (aq) ⟶ Cu(NO₃)₂ (aq) + 2Ag (s)
(a) Copper is higher than silver in the activity series of metals. It displaces silver from silver nitrate and forms copper nitrate which gives a bluish green colour in the solution.
See less(b) Cu(s) + 2AgNO₃ (aq) ⟶ Cu(NO₃)₂ (aq) + 2Ag (s)
Consider the following salts: Na ₂CO₃, NaC1, NH4C1, CH₃COONa. Which of these salts will give (i) acidic solution (ii) neutral solution and (iii) basic solution?
(i) Acidic solution - NH₄C1 (ii) Neutral solution – NaC1 (iii) Basic solution - Na₂CO₃, CH₃COONa
(i) Acidic solution – NH₄C1
See less(ii) Neutral solution – NaC1
(iii) Basic solution – Na₂CO₃, CH₃COONa
Explain the term rancidity. State any two methods to prevent rancidity in fat and oil containing foods.
Change in smell and taste of fats and oils containing food due to atmospheric oxidation is called rancidity. Methods to prevent rancidity : (i) Keep such foods in air tight containers' (ii) Flush bags of such foods like chips with an inert gas nitrogen.
Change in smell and taste of fats and oils containing food due to atmospheric oxidation is called rancidity.
See lessMethods to prevent rancidity :
(i) Keep such foods in air tight containers’
(ii) Flush bags of such foods like chips with an inert gas nitrogen.
Explain the term rancidity. State any two methods to prevent rancidity in fat and oil containing foods.
Change in smell and taste of fats and oils containing food due to atmospheric oxidation is called rancidity.
Change in smell and taste of fats and oils containing food due to atmospheric oxidation is called rancidity.
See less