SA I - Full Chemistry Test 2 - Class 10 MCQ

Lead nitrate on heating decomposes to give nitrogen dioxide , yellow solids of lead oxide and oxygen gas 

oxidation is loss of electron and reduction is gain of electrons 

Reducing agent is itself oxidized and oxidizing agent is itself reduced so  reducing agent electron losing species and oxidizing one is electron gaining species

CuSO₄ dissolves in water to give blue colour

Rusting us a chemical change and sugar dissolving in water physical change 

Energy releasing is exothermuc and energy absorbing is endothermic

It is whitish or bluish grey in colour . 

2 or more joining together to form single product is combination

Breaking  of single reactant into 2 or more is decomposition 

Both oxidation and reduction occurring simultaneously is redox reaction 

More reactive metal displacing less reactive metal from its salt displacement reaction

Rancidity is presence of foul smell in food 

Loss of hydrogen is oxidation and gain is reduction 

Rusting occurs in presence of air and moisture

Hydrogen gas goes off with a pop sound 

conservation of mass is reactants equal to products in a reaction 

exothermic reaction is accompanied by increase in tempersture

Evolution of gas is due to chemical reaction 

 Reaction will take place between Fe and CuSO₄ and Fe will displace Cu from CuSO₄

Quick lime when dissolved in water forms calcium hydroxide

Rust is hydrated iron oxide 

Silver on exposure to sulphur compoundsgets tarnished due to formation of silver sulphide

Hydrogen gas produces pop sound when burning splinter is brought near it

Rancidity caused due to oxidation 

calcium oxide dissolved in water to whitewash walls 

gold is at the bottom of the reactive series so least reactive 

corrosion is forming of a brown coloured flaky substance

Mercury is a liquid at room temperature. It is used in making thermometers. The best conductor of heat and electricity is silver. Lead is a poor conductor of heat. Sodium is so soft that it can be cut with a knife.

Froth floatation process is a process employed for the concentration or enrichment of a sulphide ore. Roasting is used for the conversion of ore to metal oxide. Reduction by carbon is used for the conversion of oxide to the metallic form. Electrolysis is employed for the refining of metal like copper.

Chemical reduction is used for enrichment of oxide ores. Hydraulic washing, Magnetic separation and Froth floatation method are used for the concentration of an ore. Hydraulic washing is based on the differences in gravities of the ore and the gangue particles. Froth floatation process is a process employed for the concentration or enrichment of a sulphide ore.

They are called Periods and we have seven periods in the long form of periodic table. 

. 

Solubility of alcohols in water decreases with increasing molecular weight. The first three alcohols (methanol, ethanol and propanol) are completely miscible. Each alcohol consists of a carbon chain (always non-polar) and a OH group (which is polar). The solubility of alcohols starts to decrease with butanol. Alcohols are considered immiscible after heptanol. 
Boiling point of alcohols increases with increasing molecular weight. The boiling point of alcohols increases as the length of the hydrocarbon chain increases.

Ethanol and propanol are alcohols and contain the functional group -OH. Ethanol is C₂H₅OH and propanol is C₃H₇OH. Ethanoic acid contains the carboxylic group (-COOH).

The element is Sulphur. Sulphur is used to manufacture sulphuric acid and in the vulcanisation of rubber. S + 2HNO₃ → H₂SO₄ + 2NO

Carbon is a tetravalent element and does not lose or gain electrons easily to form electrovalent bonds. It forms covalent bonds with other elements.

HCl being an acid turns blue litmus red. 
HCl reacts with zinc metal to evolve hydrogen gas.
HCl reacts with solid sodium carbonate (Na₂CO₃) to evolve carbon dioxide (CO₂) gas.

It's a displacement as well as a redox reaction 

Calcium reacts with cold water (less violently as compared to the reaction of sodium with water) to form calcium hydroxide and hydrogen gas. Bubbles of hydrogen gas formed during the reaction stick to the surface of calcium and calcium pieces start floating in the water.

Calcium hydroxide when dissolved in water is an exothermic reaction and produces an alkaline media