Chemistry - Study Mode
[#161] Magnalium is an alloy of
Correct Answer
(A) Aluminium and Magnesium
Explanation
Solution: Magnalium is an aluminium alloy with 1.5 to 2% magnesium and small amounts of copper, nickel, and tin. Some alloys, intended for particular uses at the cost of poor corrosion resistance, may consist of up to 50% magnesium. It finds use in engineering and pyrotechnics. Alloys with smaller amounts of magnesium (about 5%) exhibit greater strength, greater corrosion resistance, and lower density than pure aluminium. Such alloys are also more workable and easier to weld than pure aluminium. Alloys with high amounts of magnesium (around 50%) are brittle and more susceptible to corrosion than aluminium. Although they are generally more expensive than aluminium, the high strength, low density, and greater workability of alloys with low amounts of magnesium leads to their use in aircraft and automobile parts.
[#162] Magnetite is
Correct Answer
(B) Fe 3 O 4
Explanation
Solution: Magnetite is a rock mineral and one of the main iron ores, with the chemical formula Fe₃O₄.
[#163] In which of the following states maximum iron ore is found ?
Correct Answer
(B) Fe 2 O 3
[#164] Food cans are coated with tin and not with zinc because
Correct Answer
(C) Zinc is more reactive than tin
Explanation
Solution: Food cans are coated with tin and not with zinc because zinc is above the tin in reactivity series means more reactive than tin and can react with food elements preserved in it.
[#165] Cinnabar is an ore/mineral of
Correct Answer
(D) Mercury
Explanation
Solution: Cinnabar, mercury sulphide (HgS), the chief ore mineral of mercury. It is commonly encountered with pyrite, marcasite, and stibnite in veins near recent volcanic rocks and in hot-springs deposits.