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nikitadnepr [17]
3 years ago
12

Suppose a system returns to its original overall, internal energy ((∆U) after the following changes. In step 1, 25 J of work is

done on the system as it releases 37 J of energy as heat. If, in step 2, the system performs 12 J of work, how much heat is transferred?
Chemistry
1 answer:
Brums [2.3K]3 years ago
6 0

Answer:

Heat transfer in step 2 = 47.75 J

Explanation:

Internal energy = heat + work done

U = Q + W

In a cyclic process the total internal energy change of the system = 0.

In the process there are two steps. The total heat exchange in the process is the sum of heat exchanges in the two processes.

We have to find the heat exchange in step 2.

In step 1,

W = 1.25 J          Q = -37 J

U_{1} = -37 + 1.25 = -35.75 J

In step 2, the internal energy change will be negative of that in step 1.

U = 35.75 J

W = -12 J

U = Q + W

35.75 = Q -12

Q = 47.75 J

Heat transfer in step 2 = 47.75 J

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Lemur [1.5K]

Answer;

A) Stage 1: Chlorophyll captures light energy. Stage 2: Light energy is converted to chemical energy.

Explanation;

-Photosynthesis is the process by which green plants use energy from the sun, water and carbon dioxide to make organic compounds such as simple sugars together with release of oxygen.

-The process occurs in tow stages; light-dependent stage and light independent stage. During light dependent stage, chlorophyll absorbs sunlight and uses it to split water molecules into hydrogen ions and oxygen atoms. In the light independent stage carbon (iv) dioxide is fixed and the result is organic compound; the light energy is converted to chemical energy.

4 0
3 years ago
What reaction will take place if h2o is added to a mixture of nanh2/nh3? draw the products of the reaction (without sodium ion)?
Maru [420]

When sodium amide i.e.NaNH_{2} reacts with water i.e. H_{2}O results in the formation of sodium hydroxide i.e. NaOH and ammonia NH_{3}.

The chemical reaction is given by:

NaNH_{2}+H_{2}O\rightarrow NH_{3}+NaOH

Now, when ammonia i.e.NH_{3} reacts with water results in the formation of ammonium hydroxide i.e. NH_{4}OH

The chemical reaction is given by:

NH_{3}+H_{2}O\rightarrow NH_4OH

Thus, the products of the above reactions are ammonia and ammonium hydroxide (without sodium ion).

The structures of the products are shown in figure (1): ammonium hydroxide and figure (2) ammonia.


8 0
3 years ago
How many MOLECULES are in 50.0 grams of lithium phosphate?
Ray Of Light [21]
Answer: 2.60 x 10^23 molecules


50.0 grams x (1 mol/115.79 grams) = 0.431816219 moles

0.431816219 mol x (6.02 x 10^23 molecules/1 mol) = 2.599533638 x 10^23 molecules (final answer is rounded)
8 0
3 years ago
When salt is dissolved in water, what happens to the water
choli [55]

Answer:

<em>When salt is dissolved in water</em>, many physical properties change, among them the so called colligative properties:

  • The vapor pressure of water decreases,
  • The boiling point increases,
  • The freezing point decreases, and
  • Osmotic pressure appears.

Explanation:

Colligative properties are the physical properties of the solvents whose change is determined by the number of particles (moles or ions) of the solute added.

The colligative properties are: vapor pressure, boiling point, freezing point, and osmotic pressure.

<u>Vapor pressure</u>:

The vapor pressure is the pressure exerted by the vapor of a lquid over its surface, in a closed vessel.

The vapor pressure increases when a solute is added, because the presence of the solute causes less solvent molecules to be near the surface ready to escape to the vapor phase, which means that the vapor pressure is lower.

<u>Boiling point</u>:

The boiling point is the temperature at which the vapor pressure of the liquid equals the atmospheric pressure. Since we have seen that the vapor pressure of water decreases when a solute occupies part of the surface, now more temperature will be required for the water molecules reach the atmospheric pressure. So, the boiling point increases when salt is dissolved in water.

<u>Freezing point</u>:

The freezing point is the temperarute at which the vapor pressure of the liquid and the solid are equal. Since, the vapor pressure of water with salt is lower than that of the pure water, the vapor pressure of the liquid and solid with salt will be equal at a lower temperature. Hence, the freezing point is lower (decreases).

<u>Osmotic pressure</u>:

Osmotic pressure is the additional pressure that must be exerted over a solution to make that the vapor pressure of the solvent in the solution equals the vapor pressure of the pure solvent. This additional pressure is proportional to the concentration of the solute: the higher the salt concentration the higher the osmotic pressure.

6 0
3 years ago
Hi ! Could someone help me out with this last part to my chemistry practice ? Thank you !
skelet666 [1.2K]

After 100years, sample is 250g

After 200 years, sample is 125g

After 300years, sample is 62.5 g

7 0
3 years ago
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