The correct answer is (D)
All the above are reasons the carbon , oxygen, and nitrogen cycles are vital to life on earth.
The explanation:
because :
1) Carbon, oxygen, and nitrogen are vital components of life on Earth.
2) The carbon, oxygen, and nitrogen cycles allow vital elements to return to usable form by organisms.
3)The carbon, oxygen, and nitrogen cycles are an important interface between biotic and abiotic factors
4) They are all biogeochemical cycles.
5) They all involve an interaction between living and nonliving elements.
6)They are all part of the Earth system.
Answer: Th enthalpy of combustion for the given reaction is 594.244 kJ/mol
Explanation: Enthalpy of combustion is defined as the decomposition of a substance in the presence of oxygen gas.
W are given a chemical reaction:
To calculate the enthalpy change, we use the formula:
This is the amount of energy released when 0.1326 grams of sample was burned.
So, energy released when 1 gram of sample was burned is = 
Energy 1 mole of magnesium is being combusted, so to calculate the energy released when 1 mole of magnesium ( that is 24 g/mol of magnesium) is being combusted will be:
To calculate the mass of Fe formed in a) we get first the limiting reactant between Fe2O3 and CO. Given the masses, the ratio of Fe2O3 is 1.33 while that of CO is 1.67. Hence the limiting reagent is Fe2O3. The mass of Fe formed is 148.98 grams. In b, the needed CO is only 112.04 grams. Hence, the excess is 27. 96 grams.
I believe the answer is A
Answer:
B
Explanation:
The electrochemical series can be used to check if a particular element has a greater activity than the other. Firstly, on the electrochemical series, it can be seen that lead is at a higher position compared to mercury. All things being equal, it will show a higher activity than mercury and hence can knock it off its salt.
Although it is the Overall standard electrode potential that tells us if a reaction is feasible or not, we can use the activity series to quickly discern if the reaction is possible or not. The overall standard electrode potential of both is positive which makes the reaction to be feasible and hence lead can display mercury off its salt
