If you were to measure the mass of magnesium and hydrochloric acid before combining them in the test tube, how would that mass c
2 answers:
Answer:
The mass of left over reactants after the reaction will be less than that of the mass of Magnesium and hydrochloric acid before the reaction as the reactants react to form the products.
Explanation:
The balanced chemical equation representing the reaction of Mg and HCl:
As per the Law of conservation of mass, the total mass of reactants before the reaction will be equal to the total mass of products after the reaction. So, if one of the reactant is present in excess, it would be left unconsumed after the reaction and the mass of the left over reactant will be less than the initial mass of the reactants as the reactants undergo stoichiometric chemical reaction to form the products. But if we consider the mass of reactants and mass of products formed it must be equal as per the Law of conservation of mass which states that mass is neither created nor destroyed it changes.
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Answer:
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Explanation:
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Explanation:
The reaction equation will be as follows.
Hence, moles of Na = moles of electron used
Therefore, calculate the number of moles of sodium as follows.
No. of moles =
= (as 1 kg = 1000 g)
= 195.65 mol
As, Q = where F = Faraday's constant
=
= mol C
Relation between electrical energy and Q is as follows.
E =
Hence, putting the given values into the above formula and then calculate the value of electricity as follows.
E =
=
=
As 1 J = kWh
Hence, kWh
= 3.39 kWh
Thus, we can conclude that 3.39 kilowatt-hours of electricity is required in the given situation.
Answer:
<u>D. It will decrease by a factor of 4</u>
Explanation:
According to the question , the equation follows :
Rate law : This states the rate of reaction is directly proportional to concentration of reactants with each reactant raised to some power which may or may not be equal to the stoichiometeric coefficient.
.................(1)
STEP": First, find out the power "a" and "b"
a+b = 3 (because it is given that the reaction follow 3rd order-kinetics)
According to question, <u><em>doubling the concentration of the first reactant causes the rate to increase by a factor of 2 means,</em></u>
r' = 2r if [A'] = 2[A]
Here [B] is uneffected means [B']=[B]
hence new rate =
Put the value of [A'] , [B'] and r' in the above equation:
...........(2)
Divide equation (1) by (2) we , get
Here A and A cancel each other
B and B cancel each other
We get,
1^b = 1 ( power of 1 = 1)
This is possible only when a = 1
We know that : a + b = 3
1 + b = 3
b =3 -1 = 2
b = 2
Hence the rate law becomes :
<u>.............(3)</u>
Look in the question now, it is asked to calculate the concentration of [B],if cut in half
Hence
[B']=1/2[B]
Insert the value of [B'] in equation (3)
............(a)
But
..............(b)
Compare equation (a) and (b) , we get
new rate r' =
<u>r' = 1/4 r</u>