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ASHA 777 [7]
3 years ago
13

How many different sets of equivalent protons are there for para-xylene (1,4-dimethylbenzene)? only 1 two three four?

Chemistry
1 answer:
ELEN [110]3 years ago
7 0

Answer:

Two  

Step-by-step explanation:

There are two ways to determine the number sets of equivalent protons in a compound.  

(a) By substitution

Replace each H with a different group and see if you get a different compound

For example, the six CH₃ H atoms are an equivalent set, because, if I replace any one of them, I will always get the same compound: 1-chloromethyl-4-methylbenzene (Fig. 1).

Similarly, the four aromatic H atoms are an equivalent set. If I replace any one of them, I will always get the same compound: 2-chloro-1,4-dimethylbenzene (Fig. 2).

Thus, there are two sets of equivalent protons in p-xylene.

(b) By symmetry

Two atoms are equivalent if one can be converted into the other by a <em>symmetry operation</em> on the molecule.

The methyl hydrogens can be interconverted by a combination of <em>reflections</em> about the AB and CD mirror planes and by<em> </em><em>rotation</em>s about the C-C bonds to the ring (Fig. 3).

Similarly, the four aromatic H atoms can be interconverted by a combination of <em>reflections</em> about the AB and CD mirror planes.

Again, we find two sets of equivalent protons.

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Which type of bonding is characterized by overlapping orbitals that allow outer electrons of atoms to move about freely througho
Sonja [21]

Answer:

D metallic

Explanation:

The chemical bonding which rises from electrostatic attractive force between the conduction electrons and the positively charged metal ions is called metallic bonding.

<u>It is sharing of the free electrons among the structure of the positively charged ions which are known as cations. </u>

<u>In this type of bonding, these free electrons freely move in the crystal mattice of the metal.  </u>

The bonding accounts for properties of metals, such as ductility, strength,  electrical and thermal conductivity and resistivity and luster.

6 0
3 years ago
A 80.0 g piece of metal at 88.0°C is placed in 125 g of water at 20.0°C contained in a calorimeter. The metal and water come to
grandymaker [24]

Answer:

The specific heat of the metal is 0.485 J/g°C

Explanation:

<u>Step 1:</u> Data given

Mass of the piece of metal = 80.0 grams

Mass of the water = 125 grams

Initial temperature of the metal = 88.0 °C

Initial temperature of water =20.0 °C

Final temperature = 24.7 °C

pecific heat of water is 4.18 J/g*°C

<u>Step 2:</u> Calculate specific heat of the metal

Qgained = -Qlost

Q =m*c*ΔT

Qwater = - Qmetal

m(water)*c(water)*ΔT(water) = -m(metal)*c(metal)*ΔT(metal)

with mass of water = 125 grams

with c( water) = 4.18 J/g°C

with ΔT(water) = T2-T1 = 24.7 - 20 = 4.7°C

with mass of metal = 80.0 grams

with c(metal) = TO BE DETERMINED

with ΔT(metal) = 24.7 - 88.0 = -63.3 °C

125*4.18*4.7 = -80 * C(metal) * -63.3

2455.75 = -80 * C(metal) * -63.3

C(metal) = 2455.75 / (-80*-63.3)

C(metal) = 0.485 J/g°C

The specific heat of the metal is 0.485 J/g°C

3 0
3 years ago
g A spontaneous process is one in which: A. releases a large amount of heat B. may happen (is possible) C. will rapidly approach
katrin2010 [14]

Answer:

A. releases a large amount of heat

Explanation:

A reaction is said to be spontaneous if it can proceed on its own without the addition of external energy. A spontaneous reaction is not determined by the length of time, because some spontaneous reactions are completed after a long period of time. They are exothermic in nature. An example is the conversion of graphite to carbon which takes a long period of time to complete. Spontaneous reactions are known to increase entropy in a system. Entropy is the rate of disorder in a system.

In the combustion of fire, energy is released to the surroundings as there is a decrease in energy. This is an example of a spontaneous reaction because it is an exothermic reaction, which causes an increase in entropy and a decrease in energy.

7 0
3 years ago
Given: g on moon = –1.63 meters/second2
Basile [38]

The Answer is:

<u>66 meters.</u>

7 0
3 years ago
Which of the following is NOT a true statement?
Artyom0805 [142]

Answer:

c is not a true statement

8 0
3 years ago
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