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.
25 °c is the higher temperature.
Hope This Helps You!
Good Luck Studying :)
<span>C7H8
First, determine the number of relative moles of each element we have and the molar masses of the products.
atomic mass of carbon = 12.0107
atomic mass of hydrogen = 1.00794
atomic mass of oxygen = 15.999
Molar mass of CO2 = 12.0107 + 2 * 15.999 = 44.0087
Molar mass of H2O = 2 * 1.00794 + 15.999 = 18.01488
We have 5.27 mg of CO2, so
5.27 / 44.0087 = 0.119749 milli moles of CO2
And we have 1.23 mg of H2O, so
1.23 / 18.01488 = 0.068277 milli moles of H2O
Since there's 1 carbon atom per CO2 molecule, we have
0.119749 milli moles of carbon.
Since there's 2 hydrogen atoms per H2O molecules, we have
2 * 0.068277 = 0.136554 milli moles of hydrogen atoms.
Now we need to find a simple integer ratio that's close to
0.119749 / 0.136554 = 0.876937
Looking at all fractions n/m where n ranges from 1 to 10 and m ranges from 1 to 10, I find a closest match at 7/8 = 0.875 with an error of only 0.001937, the next closest match has an error over 6 times larger. So let's go with the 7/8 ratio.
The numerator in the ratio was for carbon atoms, and the denominator was for hydrogen. So the empirical formula for toluene is C7H8.</span>
Answer:
The overall cell potential must be positive.
Explanation:
What must be true for a spontaneous reaction in an electrochemical cell?
- The overall cell potential must be positive. YES. This is by convention.
- The overall cell potential must be negative. NO. By convention, a negative cell potential means the cell is not spontaneous.
- The cathode’s standard reduction potential must be positive. NO. It only has to be higher than the anode's standard reduction potential.
- The cathode’s standard reduction potential must be negative. NO. It only has to be higher than the anode's standard reduction potential.
