I’m stuck on number 2

5. A sample of benzene (C6H6), weighing 7.05 g underwent combustion in a bomb calorimeter by the following reaction:

Cloud [144]

Answer:

A sample of benzene (C6H6), weighing 7.05 g underwent combustion in a bomb calorimeter by the following reaction:

2 C6H6 (l) + 15 O2 (g) → 12 CO2 (g) + 6 H2O (l)

The heat given off was absorbed by 500 g of water and caused the temperature of the water and the calorimeter to rise from 25.00 to 53.13 oC. The heat capacity of water = 4.18 J/g/oC and the heat capacity of the calorimeter = 10.5 kJ/oC. (1) what is the ΔH of the reaction?

Explanation:

The heat energy released by the reaction = heat absorbed by calorimeter + heat absorbed by water

Heat absorbed by water = mass of water x specific heat capacity of water x change in temperature

Heat absorbed by water = 500 g x 4.18 J/g. oC x (53.13-25.00)oC

= 58791.7 J

Heat absorbed by calorimeter = heat capacity of calorimeter x change in temperature

Heat absorbed by calorimeter = 10.5 x 10^3 J /oC x (53.13-25.00)oC

=295365 J

Total heat energy absorbed = 58791.7 J + 295365 J = 354156.7 J

Number of moles of benzene given is:

number of moles = goven mass of benzene /its molar mass

=7.05 g / 78.0 g/mol

=0.0903mol

Hence, the heat released by the reaction is:

= 354156.7 J / 0.0903 mol

= 3922.00 kJ/mol

Answer:

The heat released during the combustion of 7.05g of benzene is 3922.00kJ/mol.

7 0

2 years ago

The thermochemical equation for the reaction of carbon dioxide with sulfur dioxide is shown below. How can the reaction be descr

prisoha [69]

Answer: d. has high activation energy

Activation energy is the energy that a system requires to start a certain process. Also, it is the minimum energy necessary for a given chemical reaction to occur. For a reaction to occur between two molecules, they must collide in the correct orientation and have a minimum amount of energy equal to the activation energy.

As the molecules approach, their electron clouds repel, so energy is required for the collision to occur and therefore the reaction. The activation energy comes from the heat of the system, that is, the translational, vibrational energy, etc. of each molecule. However, if this energy is not enough, the reaction will not be spontaneous.

A reaction between two molecules can be favored by supplying energy to the system. In the case raised in the question, energy equal to 1104 kJ is provided to the system to favor the next reaction

CO2 (g) + 2SO2 (g) → CS2 (g) + 3O2 (g)

Since the energy equal to 1104 kJ is included in the reactants, it can be deduced that it is the energy that is provided to the system for the reaction to occur. However, from the value of this energy it can not be said whether the system is endothermic or exothermic since it is a kinetic variable and the variables of this type do not allow predicting the thermodynamic behavior of a system.

Furthermore, it can be seen that the value of this energy is considerably high, therefore the reaction described has a high activation energy.

3 0

3 years ago

Atoms of which of the following elements are largest? A: Na OOOO

elena-14-01-66 [18.8K]

Answer:

yes answer os Na because it's electronic configuration is 1s^2,2s^2,2p^6,3s^1

5 0

3 years ago

which idea did john dalton include in his atomic theory? a. all atoms are the same size. b. atoms of the same element are identi

lapo4ka [179]

It might be c, because he came up with the plum pudding model. or it might be that atoms of the same element are identical, but that's not true cuz ions are different and isotopes are different.

5 0

3 years ago

Which of the following is true of the energy levels of electrons in shells?

anyanavicka [17]

Answer:

Option C is the correct. Valence electrons have a higher energy level than those in other filled shells

Explanation:

Electrons must lose energy to move from the first to the second shell. FALSE

The electrons always win energy to move from the first to the second shell.

All the electrons in an atom have similar energy levels FALSE.

They are not neccesary similar. In hydrogen these are the level energy -13.6 eV , -3.4 eV , -1.51 eV , -85 eV and -54 eV

Electrons do not have potential energy, just kinetic energy. FALSE

They have both.

Valencia electrons are the last electrons in the last layer. They have as much energy as possible and are responsible for forming bonds with other elements.

8 0

3 years ago