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
Leokris [45]
3 years ago
12

WORTH 20 POINTS HELP PLEASE

Chemistry
1 answer:
Damm [24]3 years ago
5 0

Answer:

The answers to your questions are below

Explanation:

Physical change is when matter changes its form but is still the same substance.

Chemical change is when matter changes its composition.

iron and oxygen from rust  It's a chemical change because iron and oxygen form a new compound different from the reactants.

iron is denser brightly when ignited . This is a chemical property because iron reacts with oxygen.

oil and water do not mix it's a physical change, oil and water are in touch but they do not react.

mercury melts at -39°C it's a physical property because mercury changes from solid to liquid but it still is mercury.

You might be interested in
Cryogenics has the potential to be useful in a variety of fields, including medicine. Suppose you have engineered a method to su
tatiyna

Explanation:

It is known that the specific heat capacity of Liver (C_{p}) is 3.59 kJ kg^{-1}.K^{-1}

It is given that :

Initial temperature of Liver = Body temperature = 37^{o}C = 310 K

Final temperature of Liver = 180 K

Relation between heat energy, mass, and change in temperature is as follows.

                        Q = m \times C_{p} \times \Delta T

Now, putting the given values into the above formula as follows.

                    Q = m \times C_{p} \times \Delta T

                    Q = 1.5 kg \times 3.59 kJ/kg.K \times (310 - 180) K

                         =  700.05 kJ

Therefore, we can conclude that amount of heat which must be removed from the liver is 700.05 kJ.

7 0
3 years ago
N204(0) + 2NO2(g)
user100 [1]

setup 1 : to the right

setup 2 : equilibrium

setup 3 : to the left

<h3>Further explanation</h3>

The reaction quotient (Q) : determine a reaction has reached equilibrium

For reaction :

aA+bB⇔cC+dD

\tt Q=\dfrac{C]^c[D]^d}{[A]^a[B]^b}

Comparing Q with K( the equilibrium constant) :

K is the product of ions in an equilibrium saturated state  

Q is the product of the ion ions from the reacting substance  

Q <K = solution has not occurred precipitation, the ratio of the products to reactants is less than the ratio at equilibrium. The reaction moved to the right (products)

Q = Ksp = saturated solution, exactly the precipitate will occur, the system at equilibrium

Q> K = sediment solution, the ratio of the products to reactants is greater than the ratio at equilibrium. The reaction moved to the left (reactants)

Keq = 6.16 x 10⁻³

Q for reaction N₂O₄(0) ⇒ 2NO₂(g)

\tt Q=\dfrac{[NO_2]^2}{[N_2O_4]}

Setup 1 :

\tt Q=\dfrac{0.0064^2}{0.098}=0.000418=4.18\times 10^{-4}

Q<K⇒The reaction moved to the right (products)

Setup 2 :

\tt Q=\dfrac{0.0304^2}{0.15}=0.00616=6.16\times 10^{-3}

Q=K⇒the system at equilibrium

Setup 3 :

\tt Q=\dfrac{0.230^2}{0.420}=0.126

Q>K⇒The reaction moved to the left (reactants)

8 0
2 years ago
Read 2 more answers
In an experiment, 3.25 g of NH3 are allowed to react with 3.50 g of O2. 4NH3 + 5O2 &gt; 4NO + 6H2O a. Which reactant is the limi
cluponka [151]

Answer:

2.61 g of NO will be formed

The limiting reagent is the O₂

Explanation:

The reaction is:

4NH₃  +  5O₂  →  4NO  +  6H₂O

We convert the mass of the reactants to moles:

3.25g / 17 g/mol = 0.191 moles of NH₃

3.50g / 32 g/mol =0.109 moles of O₂

Let's determine the limiting reactant by stoichiometry:

4 moles of ammonia react with 5 moles of oxygen

Then, 0.191 moles of ammonia will react with (0.191 . 5) / 4 = 0.238 moles of oxygen. We only have 0.109 moles of O₂ and we need 0.238, so as the oxygen is not enough, this is the limiting reagent

Ratio with NO is 5:4

5 moles of oxygen produce 4 moles of NO

0.109 moles will produce (0.109 . 4)/ 5 = 0.0872 moles of NO

We convert the moles to mass, to get the answer

0.0872 mol . 30g / 1 mol = 2.61 g

7 0
2 years ago
Which of the following is the best example of a "Scientific Question"?
Tju [1.3M]

Answer:

B

Explanation:

5 0
2 years ago
What did most people assume the earth was at the center of?
Gala2k [10]
Center of the solar system
4 0
3 years ago
Read 2 more answers
Other questions:
  • Which of the following shows both the correct formula and correct name of an acid?
    13·2 answers
  • Chelsi has talked to her artist friends about how much money they earn each year from working in the arts. She gathers these val
    12·1 answer
  • How much energy (heat) is required to convert 248 g of water from 0 oC to 154 oC? Assume that the water begins as a liquid, that
    11·1 answer
  • What atomic or hybrid orbital on sb makes up the sigma bond between sb and f in antimony(iii) fluoride, sbf3?
    10·1 answer
  • What does an emission spectrum look like?
    13·2 answers
  • A body-centered cubic unit cell has an edge length of 588 pm. What is the radius of the atoms composing the unit cell?
    15·1 answer
  • Which is the correct name of this compound CoS
    11·1 answer
  • Hòa tan hoàn toàn 1,93 gam hỗn hợp 2 kim loại Fe và Al vào dd HCl dư, sau phản ứng thu được m gam muối và 1,456 lít khí H2 ở đkt
    7·1 answer
  • Different isotopes of the same element emit light at slightly different wavelengths. A wavelength in the emission spectrum of a
    5·1 answer
  • What is the empirical formula of a compound containing 5.03 grams carbon, 0.42 grams hydrogen, and 44.5 grams chlorine?
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!