Long Answer Type
Short Answer TypeClassify the following as pure substances or mixtures: air, milk, graphite, diamond, gasoline, tap water, distilled water, oxygen, one rupee coin, 22 carat gold, steel, iron, sodium chloride, iodized table salt.
Separate the following substances into elements and compounds: Graphite, Diamond, Distilled water, Oxygen, Iron, Sodium chloride, Blue vitriol.
How will you separate the following mixtures?
(i) Oil and water
(ii) Iron-filings and saw dust.
(iii) Glass powder and sugar.
(i) Oil and water. As oil and water are usually immiscible with each other and form two separate layers, these layers can be separated with the help of separating funnel.
(ii) Iron-filings and saw dust. This mixutre can be separated by rolling a magnet into the mixture. Iron filings are attracted towards the magnet and stick to it leaving the saw dust behind.
(iii) Glass powder and sugar. The mixture is shaken with water in a beaker. Sugar dissolves in water whereas glass powder does not. The solution is filtered. Glass is left behind as residue while sugar solution is collected as filtrate. From the filtrate, sugar may be obtained by evaporation of water or by crystallisation process.
Long Answer TypeShort Answer TypeIf 6.3g of NaHCO3 are added to 15.0 g of CH3COOH solution, the residue is found to weigh 18.0g. What is the mass of CO2 released in the reaction?
Long Answer TypeState the law of constant composition or Definite proportion. Explain with suitable examples.
In an experiment 4.68 g iron oxide on reduction with hydrogen yields 3.86 g of iron. In another experiment 3.88 g of iron oxide gives 3.2 g of iron on reduction with hydrogen. Prove that the above data illustrates the law of constant proportions.
Weight of copper oxide obtained by treating 2.16 g of metallic copper with nitric acid and subsequent ignition was 2·7g. In another experiment, 1 · 15 g of copper oxide on reduction yielded 0·92g of copper. Show that the result illustrates the law of definite proportion.
Switch
