_Mg + _HCL = _MgCl2 + H2
Separate the terms on each side:
_Mg + _HCl = _MgCl2 + H2
Mg- 1 Mg-1
H-1 H-2
Cl-1 Cl-2
Mg is balanced on both sides so move on to the next (put a 1 in the space).
1Mg
There are two H's and two Cl's on the results side, so to balance the equation put a 2 as a coefficient for HCl and it'll all balance out.
2HCl
Balamced equation will be:
1Mg + 2HCL = 1MgCl2 + H2
Answer : The entropy change for the surroundings of the reaction is, -198.3 J/K
Explanation :
We have to calculate the entropy change of reaction
.

![\Delta S^o=[n_{NH_3}\times \Delta S^0_{(NH_3)}]-[n_{N_2}\times \Delta S^0_{(N_2)}+n_{H_2}\times \Delta S^0_{(H_2)}]](https://tex.z-dn.net/?f=%5CDelta%20S%5Eo%3D%5Bn_%7BNH_3%7D%5Ctimes%20%5CDelta%20S%5E0_%7B%28NH_3%29%7D%5D-%5Bn_%7BN_2%7D%5Ctimes%20%5CDelta%20S%5E0_%7B%28N_2%29%7D%2Bn_%7BH_2%7D%5Ctimes%20%5CDelta%20S%5E0_%7B%28H_2%29%7D%5D)
where,
= entropy of reaction = ?
n = number of moles
= standard entropy of 
= standard entropy of 
= standard entropy of 
Now put all the given values in this expression, we get:
![\Delta S^o=[2mole\times (192.5J/K.mole)]-[1mole\times (191.5J/K.mole)+3mole\times (130.6J/K.mole)]](https://tex.z-dn.net/?f=%5CDelta%20S%5Eo%3D%5B2mole%5Ctimes%20%28192.5J%2FK.mole%29%5D-%5B1mole%5Ctimes%20%28191.5J%2FK.mole%29%2B3mole%5Ctimes%20%28130.6J%2FK.mole%29%5D)

Therefore, the entropy change for the surroundings of the reaction is, -198.3 J/K
Answer:
Relative motion of source and observer.
Explanation:
Doppler Effect : It is the change in the observed frequency of the wave due to<em><u> relative motion of the source and object </u></em>.
In my opinion yes, as of now, almost anyone could get there hands on lets say an explosive. Have you heard of dynamite fishing? It is illegal, but it is still done once people have access to dynamite, then what ends up happening not only do marine wildlife get killed but it pollutes the water and lessens the chance of the natural cycle of life. Also there are several other factors, firstly, what will you do with an explosive once you get your hands on it? Perhaps you could just use an explosive for fun/personal entertainment...that isn't right and it could harm people. So, to conclude the harder it is for people to access explosives or even acclerants the better...and to add this can be possible by making people get like some sort of licence to use them, and let them be trained in certain conditions so that there is no regrets once they have access to them. I know my idea sounds far fetched but its a thought!
Answer:
a pure substance consists only of one element or one compound
a mixture consists of two or more different substances, not chemically joined together.
examples:
pure substance : Hydrogen gas - Diamond - Gold metal.
mixture : water and oil - mixtures of sand and water - trail mix
Explanation: