Question

Which equation obeys the law of conservation of mass? A. 2C4H10 + 2Cl2 + 12O2 7CO2 + CCl4 + 10H2O B. C4H10+ Cl2 + 2O2 7CO2 + CCl4 + 8H2O C. 2C4H10+ 2Cl2 + 12O2 4CO2 + CCl4 + H2O D. 2C4H10+ 2Cl2 + 6O2 CO2 + CCl4 + 6H2O E. 4C4H10+ 4Cl2 + 14O2 14CO2 + CCl4 + 20H2O

Answer 1

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. $2C_4H_{10}+2Cl_2+12O_2\rightarrow 7CO_2+CCl_4+10H_2O$

The mass of reactant side = $2C_4H_{10}+2Cl_2+12O_2=[8(12)+20(1)]+4(35.5)+24(16)=642g$

The mass of product side = $7CO_2+CCl_4+10H_2O=7(12)+14(16)+12+4(35.5)+20(1)+10(16)=642g$

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.