1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
olga2289 [7]
3 years ago
15

Which of the following is an indication that a substance has undergone a chemical change? No new product has been formed. The co

lor of the substance has not changed. The original constitute has not changed. The molecular structure has changed. NextReset
Chemistry
2 answers:
PtichkaEL [24]3 years ago
7 0

Answer: Option (d) is the correct answer.

Explanation:

A change causes change in chemical composition of a substance is known as a chemical change.

For example, reactivity, toxicity, combustion etc are all chemical properties.

Chemical changes lead to the formation of new compounds. As a result, there occurs change in molecular structure of a compound.

Whereas a change that does not bring any changes in chemical composition of a substance is known as a physical change.

For example, boiling point, density, volume, melting point etc are all physical properties.

Thus, we can conclude that the molecular structure has changed is an indication that a substance has undergone a chemical change.

dexar [7]3 years ago
4 0
The molecular structure has changed.
You might be interested in
HURRY PLEASE DUE TODAY
e-lub [12.9K]

Answer:

D. 9.8m/s

Explanation:

am not find. Susi fhsh.

7 0
3 years ago
Which of the following properly displays alpha decay?
tatyana61 [14]
<span>Alpha decay or α-decay is a type of radioactive decay in which an atomic nucleus emits an alpha particle (helium nucleus) and thereby transforms or 'decays' into an atom with a mass number that is reduced by four and an atomic number that is reduced by two.

You didn't list any options, but I hope this helps!
</span>
5 0
3 years ago
Predict whether the entropy change for this process is positive or negative and explain your answer. Then, predict whether the f
andrew11 [14]

The given question is incomplete. The complete question is:

Consider the spontaneous dissolution of NaCl in water: NaCl(s) → Na+(aq) + Cl −(aq) Predict whether the entropy change for this process is positive or negative and explain your answer. Then, predict whether the free energy change for the process is positive or negative and explain your answer.

Answer: The entropy change is positive. The free energy change for the process is negative and reaction is spontaneous.

Explanation:

Entropy is defined as the degree of randomness of a system. For a system in which randomness increses , the enetropy is said to increase and \Delta S is positive.

As in the given reaction : NaCl(s)\rightarrow Na^+(aq)+Cl^-(aq) , the solid is dissociating to give ions , randomness increases and thus entropy is positive.

Also the dissociation of a molecule requires energy , thus the enthalpy \Delta H is also positive as heat is absorbed by the system.

\Delta G=\Delta H-T\Delta S

\Delta G=(+ve)-T(+ve)

\Delta G=-ve when Temperature is high.

7 0
3 years ago
PLEASE HELP ASAP NO LINKS PLEASE
Zarrin [17]

Answer:

gravity

Explanation:

Gravity is the force that pulls us to the surface of the Earth, keeps the planets in orbit around the Sun and causes the formation of planets, stars and galaxies.

Hope this helped!!!

5 0
3 years ago
What is the molality of a solution made by combining 5.0 g of CaCl2 with 500.0 g of water?
ankoles [38]
Molality is defined as the number of moles of solute dissolved in 1 kg of solvent.
To calculate molality, we need to calculate the number of moles of CaCl₂.
Mass of CaCl₂ - 5.0 g
Molar mass of CaCl₂ - 111 g/mol
The number of moles of CaCl₂ - 5.0 g / 111 g/mol = 0.045 mol 
we need to then calculate the number of moles in 1 kg solvent.
number of CaCl₂ moles in 500 g water - 0.045 mol
Therefore number of moles in 1 kg water - 0.045 mol / 500g x 1000 g = 0.090 mol
Molality of CaCl₂ - 0.090 mol/kg

5 0
4 years ago
Other questions:
  • To increase the electrical force between two charges by 4 times, ________________.
    10·1 answer
  • Which of the statement about this equation is incorrect ?
    9·1 answer
  • What interactions are responsible for maintaining quaternary protein structure? Select all that apply.
    10·1 answer
  • What do we call a group that comes off of the main carbon chain
    11·1 answer
  • PLEASE HELP!!!!! AM IN A HURRY!!In at least 150 words, justify the need for a control in an experiment. Use complete sentences.
    8·2 answers
  • In this diagram of the Krebs cycle, what are the correct labels for the blanks?
    11·2 answers
  • What is mean by kinetic energy​
    9·1 answer
  • Can you think of other solutions that might be<br> acidic?
    13·2 answers
  • 2
    15·1 answer
  • Which substance is not a fossil fuel?
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!