All categories

2 years ago

When a substance is entering a phase change, the gain or loss of heat is a result of?

1 answer:

8 0

When a substance is entering a phase change, the gain or loss of heat is a result of energy gained or lost in forming or breaking intermolecular interaction.

The constant temperatures occur when a substance is undergoing a phase transition. If heat is removed from a substance , such as in freezing and condensation , then the process is exothermic . In this instance , heat is decreasing the speed of the molecules causing then move slower.

In chemistry and thermodynamics, phase transitions (or phase changes) are the physical processes of transition between a state of a medium, identified by some parameters, and another one, with different values of the parameters.

Commonly the term is used to refer to changes among the basic states of matter: solid, liquid, and gas, as well as plasma in rare cases.

For example, a phase of a thermodynamic system and the states of matter have uniform physical properties. During a phase transition of a given medium, certain properties of the medium change, often discontinuously, as a result of the change of external conditions, such as temperature, pressure, or others.

For example, a liquid may become gas upon heating to the boiling point, resulting in an abrupt change in volume. The measurement of the external conditions at which the transformation occurs is termed the phase transition. Phase transitions commonly occur in nature and are used today in many technologies.

Learn more about phase change here :

brainly.com/question/12390797

#SPJ4

You might be interested in

Which bones are shortened in brachycephalic dogs?

atroni [7]

Bones affected in brachycephalic dogs are the jaw bones, and part of the skull.

5 0

3 years ago

Read 2 more answers

Why do alligators need a warm climate?

Reptile [31]

The answer is B.They cannot produce enough heat to keep their bodies warm.

In order to survive, the alligators rely on warm weather, and they are most active when the environment is 82-92 degrees Fahrenheit. They can survive below or above this temperature range but they may spend that time struggling to stay warm or stay cool.

5 0

3 years ago

If this decay has a half life of 2.60 years, what mass of 72.5 g of sodium 22 will remain after 15.6 years

Vlad1618 [11]

Sodium-22 remain : 1.13 g

<h3>Further explanation </h3>

The atomic nucleus can experience decay into 2 particles or more due to the instability of its atomic nucleus.

Usually, radioactive elements have an unstable atomic nucleus.

General formulas used in decay:

$\large{\boxed{\bold{N_t=N_0(\dfrac{1}{2})^{T/t\frac{1}{2} }}}$

T = duration of decay

t 1/2 = half-life

N₀ = the number of initial radioactive atoms

Nt = the number of radioactive atoms left after decaying during T time

half-life = t 1/2=2.6 years

T=15.6 years

No=72.5 g

$\tt Nt=72.5.\dfrac{1}{2}^{15.6/2.6}\\\\Nt=72.5.\dfrac{1}{2}^6\\\\Nt=1.13~g$

8 0

3 years ago

The density of an aqueous solution of nitric acid is 1.64 g/mL and the concentration is 1.85 M. What is the concentration of thi

galina1969 [7]

Answer:

Mass % of the solution = 7.1067 %

Explanation:

Given :

Molarity of nitric acid solution = 1.85 M

Density of the solution = 1.64 g/mL

Molarity of a solution is defined as the number of moles of solute present in 1 liter of the solution.

$Molarity=\frac{Moles\ of\ solute}{Volume\ of\ the\ solution}$

Lets, consider the volume of the solution = 1 L

Thus,

Moles of nitric acid present in the solution:

$Molarity=\frac{Moles\ of\ solute}{Volume\ of\ the\ solution}$

$Moles of Nitric acid=Molarity \times {Volume\ of\ the\ solution}$

So,

Moles of Nitric acid = 1.85 moles

Molar mass of nitric acid = 63 g/mol

The mass of Nitric acid can be find out by using mole formula as:

$moles=\frac{Mass\ taken}{Molar\ mass}$

Thus,

$Mass\ of\ Nitric\ acid=Moles \times Molar mass}$

$Mass\ of\ Nitric\ acid=1.85 g \times 63 g/mol}$

Mass of Nitric acid = 116.55 g

Also,

$Density=\frac{Mass}{Volume}$

Given : Density = 1.64 g/mL

Also, 1 L = 10³ mL

Volume of the solution is 1000 mL

So, mass of the solution:

$Mass\ of\ the\ solution=Density \times {Volume\ of\ the\ solution}$

$Mass\ of\ the\ solution=1.64 g/mL \times {1000 mL}$

Mass of the solution = 1640 g

Mass % is defined as the mass of solute in 100 g of the solution. The formula for the calculation of mass % is shown below:

$Mass \% =\frac{Mass\ of\ the\ solute}{Mass\ of\ the\ solution} \times {100}$

So,

$Mass \%=\frac{116.55}{1640} \times {100}$

Mass % = 7.1067 %

6 0

3 years ago

The equation for the reaction between copper and nitric acid is vCu + wHNO3--->xCu(NO3)2 + yNO + zH2O Balance the equation an

lana [24]

Answer:

The coefficients of the balanced equation are:

v= 1
w= 4
x= 1
y= 2
z=2

Explanation:

The Law of Conservation of Matter, also called the Law of Conservation of Mass or the Lomonósov-Lavoisier Law, postulates that "mass is neither created nor destroyed, it is only transformed". This means that the reagents interact with each other and form new products with different physical and chemical properties than the reagents, but the amount of matter or mass before and after a transformation (chemical reaction) is always the same. In other words, then the mass before the chemical reaction is equal to the mass after the reaction.

Then, you must balance the following chemical equation:

v Cu + w HNO₃ → x Cu(NO₃)₂ + y NO + z H₂O

For that, you must first look at the subscripts next to each atom to find the number of atoms in the equation. If the same atom appears in more than one molecule, you must add its amounts

Left side: 1 copper, 1 hydrogen, 1 nitrogen and 3 oxygen.
Right side: 1 copper, 2 hydrogen, 3 nitrogen and 8 oxygen.

The coefficients located in front of each molecule indicate the amount of each molecule for the reaction. This coefficient can be modified to balance the equation, just as you should never alter the subscripts.

By multiplying the coefficient mentioned by the subscript, you get the amount of each element present in the reaction.

Generally, hydrogen and oxygen balance in the end. So you balance nitrogen first, because copper is already balanced (there is the same amount on both sides of the reaction). If w = 2, then:

Left side: 1 copper, 2 hydrogen, 2 nitrogen and 6 oxygen.
Right side: 1 copper, 2 hydrogen, 3 nitrogen and 8 oxygen.

But you see then that the oxygen is unbalanced and you have less quantity in the reagents. Then w must be greater. Being w = 4:

Left side: 1 copper, 4 hydrogen, 4 nitrogen and 10 oxygen.
Right side: 1 copper, 2 hydrogen, 3 nitrogen and 8 oxygen.

Going back to the idea of balancing nitrogen, being y = 2:

Left side: 1 copper, 4 hydrogen, 4 nitrogen and 10 oxygen.
Right side: 1 copper, 2 hydrogen, 4 nitrogen and 9 oxygen.

Balancing the hydrogen, being z = 2:

Left side: 1 copper, 4 hydrogen, 4 nitrogen and 10 oxygen.
Right side: 1 copper, 4 hydrogen, 4 nitrogen and 10 oxygen.

Since you have the same amount of each element on each side of the reaction, the reaction is balanced. Then, the balanced equation is:

Cu + 4 HNO₃ → Cu(NO₃)₂ + 2 NO + 2 H₂O

Finally:

v= 1
w= 4
x= 1
y= 2
z=2

6 0

3 years ago