Q. 60. Answer the following questions:
Q. 61. Explain why:
Q. 62. Which of the following elements are metals and which are non-metals:
Q. 63. Write the reaction of following on metals:
(a) Oxygen (b) Water (c) dilute acids
Q. 64. What will happen if 4 strip of copper is kept in mersed in a solution of silver nitrate?
Q. 65. What is meant by ore concentration? Name four common methods of ore concentration and describe them.
Q. 67. What is the difference between roasting and calcinations? Which one of the two is used for sulphide ores?
Q. 68. Describe the methods used for the refining of impure metals.
Q. 69. Give the difference between:
Q. 70. Describe the extraction of aluminium form bauxite.
Q. 71. Write the formula and the names of metals extracted form the following ores:
Q. 72. Describe be the methods used for obtaining metals of very high purity.
Q. 73. Mention any four uses of copper.
Q. 74. Write three uses of aluminium.
Q. 75. Write the main uses of the following metals:
Q. 76. What is an alloy? Write the composition and uses of main alloys.
Q. 77. Name the harmful effect of excess of (a) iron and (b) copper in the body.
Q. 78. Write difference between metals and non-metals.
Q. 79. Write the reaction of
(a) Oxygen (b) acids (c) chlorine (d) hydrogen and non-metals
Q. 80. Write the laboratory method of preparation of hydrogen. State its physical and chemical properties. Write the uses of hydrogen.
Q. 81. Write the properties of ammonia also give its uses.
Q. 82. Describe heating effect of sulphur.
Q. 83. Sate the physical and chemical properties of sulphur and mention its uses.
Q. 84. What is termite reaction?
Q. 85. What is an amalgam?
