All categories

3 years ago

Which phase change requires more heat energy, Heat of fusion or Heat of

Chemistry

2 answers:

Afina-wow [57]3 years ago

5 0

Answer:

heat of fusion

Explanation:

heat of fusion is melting which requires more heat energy than heat of vaporization

OverLord2011 [107]3 years ago

3 0

Answer:

Evaporation involves a liquid becoming a gas and sublimation is the change of a solid directly to a gas. Phase changes require either the addition of heat energy (melting, evaporation, and sublimation) or subtraction of heat energy (condensation and freezing).

Explanation:

You might be interested in

What would indicate that a physical change takes place when cooper is drawn into wire

amid [387]

Answer:

When a copper is drawn into wire the only change that occurs is change in its shape and size no change will take place into its composition that is the wires are still possessing the properties of copper metal. Thus, a physical change takes place when copper is drawn into wire.

4 0

2 years ago

The goal of this lesson:

mote1985 [20]

Answer:

1. The concentration of N₂O₄ decrease as the temperature of the system increased.

2. The formation of products was favored by the addition of heat.

3. The reaction going from right to left is exothermic.

4. N₂O₄ → 2NO₂; HR = +14 kcal.

Explanation:

Equation of the reaction is as follows: N₂O₄ ⇄ 2NO₂

The forward reaction proceeds with an increase in temperature. As the temperature of the reaction was increased, more of the N₂O₄ decomposed to form NO₂. Therefore, the concentration of N₂O₄ deceased.

2. The formation of products, that is the forward reaction leading to formation of NO₂ was favored by the addition of heat. Thus, with increase in temperature, the concentration of NO₂ increased.

3. An endothermic reaction is a type of reaction which requires energy input in the form of heat in order to proceed.

From the observations during the reaction, an increase in temperature by the addition of heat resulted in an increase in the forward reaction, therefore, the forward reaction is endothermic and the backward reaction is exothermic. Thus, the reaction in which colorless N₂O₄ is produced, is an exothermic reaction.

4. The change in enthalpy of a reaction is the difference in the heat content of reactants and products. For exothermic reactions, enthalpy change is negative, whereas for endothermic reactions, enthalpy change is positive.

The decomposition of N₂O₄ to NO₂ is an endothermic reaction. Hence, the correct chemical equation is: N₂O₄ → 2NO₂; HR = +14 kcal.

7 0

3 years ago

If the pOH of vinegar is 9.45, what is its [OH− ]?

goldfiish [28.3K]

3.55 × 10n M n = -10

6 0

4 years ago

Read 2 more answers

The weight of a sack potato in india is 50kgf. will the weight increase or decrease in bhutan. why

AfilCa [17]

Answer:

Assume that the sack was initially close to the sea level. Its weight will increase even though its mass stays the same.

Explanation:

The weight of an object typically refers to the size of the planet's gravitational attraction (a force) on this object. That's not the same as the mass of the object. The weight of an object at a position depends on the size of the gravitational field there; on the other hand, the mass of the object is supposed to be same regardless of the location- as long as the object stays intact.

Let $g$ denote the strength of the gravitational field at a certain point. If the mass of an object is $m$ , its weight at that point will be $m \cdot g$ .

Indeed, $g \approx 9.81\; \rm N \cdot kg^{-1}$ on many places of the earth. However, this value is accurate only near the sea level. The equation for universal gravitation is a more general way for finding the strength of the gravitational field at an arbitrary height. Let $G$ denote the constant of universal gravitation, and let $M$ denote the mass of the earth. At a distance $r$ from the center of the earth (where

$\displaystyle g \approx \frac{G \cdot M}{r^2}$ .

The elevation of many places in Bhutan are significantly higher than that of many places in India. Therefore, a sack of potato in Bhutan will likely be further away from the center of the earth (larger $r$ ) compared to a sack of potato in India.

Note, that in the approximation, the value of $g$ is (approximately, because the earth isn't perfectly spherical) inversely proportional to the distance from the center of the planet. The gravitational field strength

On the other hand, the weight of an object of fixed mass is proportional to the gravitational field strength. Therefore, the same bag of potatoes will have a smaller weight at most places in Bhutan compared to most places in India.

6 0

3 years ago

A 5.00 L sample of helium expands to 12.0 L at which point the

mina [271]

Answer:

1.73 atm

Explanation:

Given data:

Initial volume of helium = 5.00 L

Final volume of helium = 12.0 L

Final pressure = 0.720 atm

Initial pressure = ?

Solution:

"The volume of given amount of gas is inversely proportional to its pressure by keeping the temperature and number of moles constant"

Mathematical expression:

P₁V₁ = P₂V₂

P₁ = Initial pressure

V₁ = initial volume

P₂ = final pressure

V₂ = final volume

Now we will put the values in formula,

P₁V₁ = P₂V₂

P₁ × 5.00 L = 0.720 atm × 12.0 L

P₁ = 8.64 atm. L/5 L

P₁ = 1.73 atm

7 0

3 years ago