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
KonstantinChe [14]
2 years ago
5

Which of these are physical changes in matter chech all that apply

Chemistry
2 answers:
Bogdan [553]2 years ago
8 0

Explanation:

Changes that are unable to bring any difference in chemical composition of a substance are known as physical change.

For example, change in shape, size, mass, volume, density, boiling or freezing point etc are all physical changes.

Whereas changes that bring difference in chemical composition of a substance are known as chemical changes.

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

Hence, out of the given options physical changes are classified as follows.

  • Boiling water
  • A pencil being sharpened
  • Freezing water

serious [3.7K]2 years ago
6 0

Answer:

a pencil being sharpened

freezing water

boiling water

Explanation:

a physical change doesn't change the chemical structure of an object. That is why the other 2 are wrong

You might be interested in
How many moles are in 155 grams of aluminum
Aliun [14]

Answer:

wads

Explanation:

wadsdw

8 0
3 years ago
If 4520 kj of heat is needed to boil a sample of water, what is the mass of water
Cerrena [4.2K]

Answer:

1,085g of water

Explanation:

If we have the value 4520kj is because the question is related to Energy and heat capacity. In this case, the law and equation that we use is the following:

                                                  Q= m*C*Δt  where;

Q in the heat, in this case: 4520kj

m is the mas

Δt= is the difference between final-initial temperature (change of temperature), in this exercise we don´t have temperatura change.

In order to determine the mass, I will have the same equation but finding m

                                          m= Q/C*Δt    without   m=Q/C

So: m= 4,520J/4.18J/g°C

      m= 1,0813 g

5 0
3 years ago
Nitrogen dioxide and water react to form nitric acid and nitrogen monoxide, like this:
posledela

Answer: The value of the equilibrium constant Kc for this reaction is 3.72

Explanation:

Equilibrium concentration of HNO_3 = \frac{15.5g}{63g/mol\times 9.5L}=0.026M

Equilibrium concentration of NO = \frac{16.6g}{30g/mol\times 9.5L}=0.058M

Equilibrium concentration of NO_2 = \frac{22.5g}{46g/mol\times 9.5L}=0.051M

Equilibrium concentration of H_2O = \frac{189.0g}{18g/mol\times 9.5L}=1.10M

Equilibrium constant is defined as the ratio of concentration of products to the concentration of reactants each raised to the power their stoichiometric ratios. It is expressed as K_c  

For the given chemical reaction:

2HNO_3(aq)+NO(g)\rightarrow 3NO_2(g)+H_2O(l)

The expression for K_c is written as:

K_c=\frac{[NO_2]^3\times [H_2O]^1}{[HNO_3]^2\times [NO]^1}

K_c=\frac{(0.051)^3\times (1.10)^1}{(0.026)^2\times (0.058)^1}

K_c=3.72

Thus  the value of the equilibrium constant Kc for this reaction is 3.72

5 0
2 years ago
In which location would you expect to find the greatest species diversity?!
Crank
I believe the answer is Canada!
5 0
3 years ago
Ions that have the same electron configuration are called
Katena32 [7]
Such ions are said to be isoelectronic
3 0
3 years ago
Other questions:
  • Suppose you place a hot pack into a vacuum chamber and the hot pack caused the temperature to rise from 21 degrees to 23 degrees
    10·1 answer
  • How does electronegativity impact polarity of molecules?
    9·1 answer
  • Na+ and Cl- __________ ___________________________ Na+ and PO4 3- __________ ___________________________ Na+ and SO4 2- ________
    13·1 answer
  • What is the strong nuclear force
    6·1 answer
  • Help please for chemistry class
    14·1 answer
  • Which particle has an electronic structure of 2.8.8?
    12·2 answers
  • At 258C, Kp 5 2.9 3 1023 for the reactionNH4OCONH21s2m 2NH31 g21 CO21 g2In an experiment carried out at 258C, a certain amount o
    11·1 answer
  • What mass of precipitate (in g) is formed when 250.0 mL of 0.150 M CuCl₂ is mixed with excess KOH in the following chemical reac
    10·1 answer
  • Determine the empirical formula of a compound containing 47.37 grams of carbon, 10.59 grams of hydrogen, and 42.04 grams of oxyg
    10·1 answer
  • What are metalloids?
    8·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!