To balance a chemical reaction, it is important to remember that the number of atoms of each element in the reactants and the product side should be equal. This is to follows the law of conservation of mass where mass cannot be created or destroyed. So, the total mass that is used to react should have the same value of the total mass of the substances produced from the reactants. The balanced chemical reaction would be written as follows:
<span> 2h2 + o2 = 2h2o
Reactant = Product
H = 4 = 4
O = 2 = 2
Therefore, the correct coefficient for the hydrogen gas would be 2.</span>
the combustibility of calcium is relitivly high
Unsaturated hydrocarbons are those in which each carbon atom is attached to as many hydrogen atoms as it possibly can. There can be no double bonds or non-hydrogen functional groups, since these detract from the maximum possible number of hydrogens that each carbon can be attached to (in the case of double bonds, two carbons are bonded to each other when they could alternately be bonded to one more hydrogen each).
All of the alkanes (including the cycloalkanes) are saturated hydrocarbons. Substituted alkanes, alkenes, alkynes, and their cyclic counterparts are all unsaturated.
Explanation:
Rate law is defined as the rate of a reaction is directly proportional to the concentration of reactants at constant temperature.
![Rate \propto [\text{concentration of reactant}]^{n}](https://tex.z-dn.net/?f=Rate%20%5Cpropto%20%5B%5Ctext%7Bconcentration%20of%20reactant%7D%5D%5E%7Bn%7D)
= k ![[\text{concentration of reactant}]^{n}](https://tex.z-dn.net/?f=%5B%5Ctext%7Bconcentration%20of%20reactant%7D%5D%5E%7Bn%7D)
where, k = rate constant
n = order of reaction
For the given reaction, 
Hence, its rate will be as follows.
Rate = ![k[H_{2}][NO]](https://tex.z-dn.net/?f=k%5BH_%7B2%7D%5D%5BNO%5D)
Also, it is known that slowest step in a chemical reaction is the rate determining step.
Hence, for the given rate law correct reaction is as follows.
Step 1 : 
(slow)
Balancing this equation it becomes 
(slow)
Step 2: 
(fast)
