Answer: Option (b) is the correct answer.
Explanation:
When the cake is baked then due to the heat provided to it there will occur movement of its molecules.
As a result, molecules will gain kinetic energy due to which there will occur collisions between them.
Also, 
Hence, more is the heat provided to the cake more will be the kinetic energy of its molecules due to which when we touch it, it feels hot.
Thus, we can conclude that molecules in the cake are moving faster than molecules in the skin, best explains why the cake feels hot.
4.9 moles of salt are required to be added to 1 kg water to change the boiling temperature
by 5°C.
<h3>What is the moles of Salt required to change the temperature of water by 5°C?</h3>
Based on the given equation, the molality of the solution is calculated as follows:
- Molality = change in temperature/ Kb × I
Change in temperature = 5 °C
Kb = 0.51
i = 2
Molality = 5/0.51 × 2 = 4.9 molal
Also, Molality = moles/kg of water
Moles of salt = molality × kg of water
Moles of salt = 4.9 × 1 = 4.9 moles.
Therefore, 4.9 moles of salt are required to be added to 1 kg water to change the boiling temperature
by 5°C.
Learn more about molality at: brainly.com/question/9149034
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The answer for the following problem is mentioned below.
- <em><u>Therefore the mass of an object is 14.16 grams.</u></em>
Explanation:
Force:
The push or pull on an object with mass that cause change in the velocity
It is a vector quantity.
The formula to calculate the force is:
F = m × a
Given:
Force (F) = -136 N
acceleration (a) = -9.6 m/s^2
To calculate:
mass of the object (m)
We know that,
<em>F = m × a</em>
where,
F represents the force of the object
m represents mass of an object
a is acceleration of an object
From the equation;
-136 = m × -9.6
m = 
m = 14.16 grams
<em><u>Therefore the mass of an object is 14.16 grams.</u></em>
Answer : The final temperature of the water is, 
Explanation : Given,
Mass of benzene = 8.600 g
Molar mass of benzene = 78 g/mole
First we have to calculate the moles of benzene.
Now we have to calculate the energy of combustion.
The given balanced chemical reaction is:
According to reaction,
As, 2 moles of benzene gives 6542 kJ of energy on combustion.
So, 0.1103 mole of benzene gives 
of energy on combustion.
Now we have to calculate the final temperature of the water.
Formula used : 
where,
= heat released = 360.7913 kJ = 36079.13 J
= mass of water = 5691 g
= specific heat of water= 
= final temperature = ?
= initial temperature = 
Now put all the given values in the above formula, we get:
Therefore, the final temperature of the water is,
The net ionic equation : Ba²⁺ + SO₄²⁻ ⇒ BaSO₄ (s)
<h3>Further explanation </h3>
The electrolyte in the solution produces ions.
The equation of a chemical reaction can be expressed in the equation of the ions
In the ion equation, there is a spectator ion that is the ion which does not react because it is present before and after the reaction
When these ions are removed, the ionic equation is called the net ionic equation
For gases and solids including water (H₂O) can be written as an ionized molecule
So only the dissolved compound is ionized ((expressed in symbol aq)
Barium sulfate can be formed from the reaction:
Ba(NO₃)₂(aq) + Na₂SO₄(aq)⇒BaSO₄(s)+2NaNO₃(aq)
For full ionic equation :
Ba²⁺ + 2NO₃⁻ + 2 Na⁺ + SO₄²⁻ ⇒ BaSO₄ (s) + 2 Na⁺ + 2 NO³⁻
by removing spectator ions (2NO₃⁻ and 2 Na⁺), the net ionic equation :
<em>Ba²⁺ + SO₄²⁻ ⇒ BaSO₄ (s) </em>
