10th Science Qz (Chemical reactions, acid-base & metal-nonmetal)

Sour taste of lemon is due to which acid

• Oxalic acid

• Citric acid

• Acetic acid

• HCl

Gypsum on heating to 373K is converted into (a)  

Name the type of reaction going on

• Combination

• Neutralization

• Displacement

• Decomposition

thermite reaction is used for which purpose

• to weld broken pieces of iron

• applying layering of zinc on iron

• photography

• making bleaching powder

A solution having pH 4 turns .............. litmus to............ .

(a)  

Melting point of gallium and cesium is ......

• very high

• very low

• low to high

• none of above

A very reactive metal, kept in kerosene oil, reacts with water and libearted hydrogen catches fire. Identify

• Iron

• Gold

• Aluminium

• Sodium

Solder is an alloy of

• Cu and Zn

• Cu and Sn

• Pb and Sn

• Mg and Hg

Lead nitrate decomposes by which process

• photolysis

• electrolysis

• thermolysis

• all of the above

copper on heating in air turns black due to formation of -

• copper carbonate

• copper hydroxide

• copper sulphide

• copper oxide