Answer : The correct option is A.
Explanation :
Law of conservation of mass : In the chemical reaction, the mass of reactant must be equal to the mass of product.
A. 
The mass of reactant side = ![2C_4H_{10}+2Cl_2+12O_2=[8(12)+20(1)]+4(35.5)+24(16)=642g](https://tex.z-dn.net/?f=2C_4H_%7B10%7D%2B2Cl_2%2B12O_2%3D%5B8%2812%29%2B20%281%29%5D%2B4%2835.5%29%2B24%2816%29%3D642g)
The mass of product side = 
This means, the mass of product is equal to the mass of reactant. The mass remains conserved and obeys the law of conservation of mass.
The reaction B, C, D, E does not obey the law of conservation of mass.
Therefore, Only reaction A obey the law of conservation of mass.
Answer:
C. single replacement
Explanation:
In a single replacement reaction, one atom replaces another.
The general form of a single replacement reaction is: A + Bc ⇒ Ac + B
A + B × c ⇒ B + A × c
↓ ↓ ↓ ↓ ↓ ↓
Fe + Pb(NO₃)₂ ⇒ Pb + Fe(NO₃)₂
Iron switched places with lead so the reaction is a single replacement reaction.
Hope this helps.
Reactants are what make up the product.
Answer: Option (C) is the correct answer.
Explanation:
Biopower means production of electricity with the help of biomass. The unused wood, crops, agricultural residue, animal residue etc when burned then they help in generating biopower.
It is a renewable energy. Since biomass is readily available in most of the places. Therefore, the advantage of biopower is that it is also readily available in most places.
For example, bacterial decay produces a certain amount of heat which further helps in the production of energy.
The main pieces of evidence that an exothermic reaction has occurred is an increase in temperature due to the release of energy, a release of energy in the form of light, or a release of gas.
