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andre [41]
3 years ago
7

Review energy changes by identifying the correct statements about each reaction.

Chemistry
1 answer:
Grace [21]3 years ago
5 0

Answer: The reaction is exothermic

The \Delta H value is negative.

Heat is a product.

Explanation:

2H_2(g)+O_2(g)\rightarrow 2H_2O(l)+136.6kcal

Endothermic reactions are defined as the reactions in which energy of the product is greater than the energy of the reactants. The total energy is absorbed in the form of heat and \Delta H for the reaction comes out to be positive.

Exothermic reactions are defined as the reactions in which energy of the product is lesser than the energy of the reactants. The total energy is released in the form of heat and \Delta H for the reaction comes out to be negative.

The substances which are written on the left side of the arrow are reactants and the substances which are written on the right side of the arrow are products. Thus heat is a product.

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What is the condensed structural formula of the product of the reaction of 2,7-dimethyl-4-octene with hydrogen and a metal catal
gavmur [86]
  The  condensed  structural  formula  of the  product  of the  reaction of 2,7-dimethyl-4-octene  with hydrogen   and metal  catalyst.

 Ch3 CH(CH3) CH2 CH2 CH2 CH2 CH(CH3) CH3

Equation  is  as follows

 CH3 CH(CH3) CH2  C=C CH2 CH(CH3)  CH3  +  H2
→

CH3 CH(CH3)CH2 CH2 CH2 CH2 CH(CH3) CH3

metal catalyst  example is nickel  and the name  of structure formed is 
2,7-  dimethyl octane
6 0
3 years ago
The formula K₂S indicates that _______.
Pachacha [2.7K]
The subscriot 2 means that in the formula there are two parts of K, and the subscript 1 (implicit) for S, indicates that there is one part of S.

This is, the formula gives the ratio of the elements K and S in the compound, which is:

2 atoms of K : 1 atom of S.

Answer: there are 2 atoms of K and 1 atom of S in a molecule of K2S.
5 0
3 years ago
He isotope 62(over28ni has the largest binding energy per nucleon of any isotope. calculate this value from the atomic mass of n
irina [24]
The atomic mass of the isotope Ni ( 62 over 28 ) = 61.928345 amu.
Mass of the electrons: 28 · 5.4584 · 10^(-4 ) amu = 0.0152838 amu ( g/mol )
Mass of the nuclei:
61.928345 amu - 0.0152838 amu = 61.913062 amu (g/mol)
The mass difference between a nucleus and its constituent nucleons is called the mass defect.
For Ni ( 62 over 28 ): Mass of the protons: 28 · 1.00728 amu = 28.20384 amu
Mass of the neutrons: 34 · 1.00866 amu = 34.299444 amu
In total : 62.49828 amu
The mass defect = 62.49828 - 61.913062 = 0.585218 amu
Nucleus binding energy:
E = Δm · c² ( the Einstein relationship )
E = 0.585218 · ( 2.9979 · 10^8 m/s )² · 1 / (6.022 · 10^23) · 1 kg / 1000 g =
= 0.585218 · 8.9874044 · 10 ^16 : (6.022 · 10^23) · 0.001 =
= ( 5.2595908 : 6.022 ) · 0.001 · 10^(-7 ) =
= 0.0008733 · 10^(-7) J = 8.733 · 10^(-11) J
The nucleus binding energy per nucleon:
8.733 · 10^(-11) J : 62 =  0.14085 · 10 ^(-11) =
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3 years ago
How many moles of silver are there in 6.9 x 10^28 silver atoms?
Juli2301 [7.4K]

Answer:

1.2 x 10⁵ moles Ag (2 sig. figs.)

Explanation:

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6 0
2 years ago
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