A reaction will only be spontaneous if the change in enthalpy is more negative than the product of −tδs is positive.

Describe how changing the particles changed the atom

Zanzabum

Bonds between atoms break and new ones form and energy is either given out or taken in

5 0

3 years ago

Using a value of Ksp = 1.8 x 10-2 for the reaction PbCl2 Pb+2(aq) + 2Cl -(aq). If the value of Ksp was determined to be only 1.2

ohaa [14]

Answer:

The correct answer is option D, that is, the ions are now combining to reduce their concentrations.

Explanation:

On the basis of the chemical equation:

PbCl₂ (s) ⇒ Pb²⁺ (aq) + 2Cl⁻ (aq)

It is mentioned that the value of Ksp is 1.8 × 10⁻²

As the solubility product is very less or negligible for this reaction that signifies that the ions produced are getting combined, resulting in the reduction of the concentration of the ions and enhancing the formation of the solid lead chloride. Therefore, they associate together to produce solid lead chloride.

4 0

3 years ago

What happens to temperature and kinetic energy of particles during a change of state

Wittaler [7]

When a substance is changing state, its temperature remains constant. This is because energy is used to increase/decrease kinetic energy of the molecules of the substance, increasing/decreasing the inter-molecular distance and overcoming the energy bonds present between the molecules. Therefore, no energy is used to raise the temperature of the substance and therefore it remains constant

3 0

3 years ago

The temperature of a freezer started at 18şc. After cooling for a few hours, the freezer had a temperature of –12şc. What is the

andre [41]

20 minus 2 plus 1 equals negative -2000000

8 0

3 years ago

When a 0.245-g sample of benzoic acid is combusted in a bomb calorimeter, the temperature rises 1.643 ∘C . When a 0.260-g sample

sveticcg [70]

Answer:

The heat of combustion per moles of caffeine is 4220 kJ/mol

Explanation:

Step 1: Data given

⇒ When benzoic acid sample of 0.245 grams is burned the temperature rise is 1.643 °C

⇒ When 0.260 gram of caffeine is burned, the temperature rise is 1.436 °C

⇒ Heat of combustion of benzoic acid = 26.38 kJ/g

Step 2: Calculate the heat released: for combustion of benzoic acid

0.245 g benzoic acid * 26.38 kJ/g = 6.4631 kJ

Step 3: Calculate the heat capacity of the calorimeter:

c = Q/ΔT

Q = 6.4631 kJ / 1.643°C = 3.934 kJ/ °C

Step 4: Calculate moles of a 0.260 g sample of caffeine:

Moles caffeine = Mass caffeine / Molar mass caffeine

0.260 grams/ 194.19 g/mol = 0.0013389 moles

Step 5: Calculate heat released: for combustion of caffeine

Q = c * ΔT

Q = 3.934 kJ/°C * 1.436 °C = 5.65 kJ

Step 6: Calculate the heat of combustion per mole of caffeine

5.65 kJ / 0.0013389 moles = 4219.9 kJ/mol ≈ 4220 kJ/mol

The heat of combustion per moles of caffeine is 4220 kJ/mol

4 0

4 years ago