Question 2 (1 point)
Which of the following does NOT involve a chemical reaction?
Fallen leaves decay in a compost pile.
Leaves change color in the fall.
O A fire burns a pile of fallen leaves.
A pond freezes over in the winter.

Answers

Answer 1

Answer:

D. A pond freezing over is not a chemical reaction, it is a physical reaction.


Related Questions

Mercury(II) oxide decomposes to form mercury and oxygen, like this:
2Hg (l) + O2 (g) → 2HgO (s)
At a certain temperature, a chemist finds that a reaction vessel containing a mixture of mercury(II) oxide, mercury, and oxygen at equilibrium has the following composition:
compound amount
Hg 14.7g
O2 13.4g
HgO 17.8g
Calculate the value of the equilibrium constant for this reaction. Round your answer to significant digits. Clears your work. Undoes your last action. Provides information about entering answers.

Answers

Solution :

For the reaction given :

[tex]$\text{2Hg}_{(l)}+\text{O}_2_{(g)} \rightarrow \text{2HgO}_{(s)}$[/tex]

Thus we know that the equilibrium constant [tex]$K_c$[/tex] contains aqueous an dgas species only.

∴       [tex]$K_c=\frac{1}{[O_2]}$[/tex]    ............(1)

Now at the equilibrium, an amount of the 13.4 g of oxygen was found in the vessel of 6.9 liters. For determining the concentration of the oxygen gas, we use :

[tex]$[O_2]= \frac{n_{O_2}}{V_{soln}}$[/tex]  ...................  (2)

Here, [tex]$n_{O_2}$[/tex] = no. of moles of oxygen gas (mol)

         [tex]$V_{soln}$[/tex] = volume of solution (L)

Therefore the number of moles of the oxygen gas is calculated by directly using the molecular weight (31.9988 g/mol) as the conversion factor.

∴      [tex]$n_{O_2}= 13.4 \ g \times \frac{\text{1 mol}}{31.9988 \ g}$[/tex]

              = 0.418 mol

Now substituting the known values in (2), we can find the equilibrium concentration of the oxygen gas :

[tex]$[O_2] =\frac{0.418 \ \text{mol}}{6.9 \ \text{L}}$[/tex]

     = 0.0605 M

Therefore substituting the result in (1), the equilibrium constant for the reaction is :

[tex]$K_c=\frac{1}{0.0605}$[/tex]

    = 16.52

Which of the following is the correct decreasing order of hydrogen ions concentrations?

Answers

Answer: A> B> C > D> E

Explanation:

pH or pOH is the measure of acidity or alkalinity of a solution.

pH is calculated by taking negative logarithm of hydrogen ion concentration.

[tex]pH=-\log [H^+][/tex]

a) Solution A: pH =2  

[tex][H^+]=10^{-2}[/tex]

b) Solution B: pH =5  

[tex][H^+]=10^{-5}[/tex]

c) Solution C: pH = 7  

[tex][H^+]=10^{-7}[/tex]

d) Solution D: pH = 8  

[tex][H^+]=10^{-8}[/tex]

e) Solution E: pH =13

[tex][H^+]=10^{-13}[/tex]

Thus the decreasing order of hydrogen ion concentration is A> B> C > D> E

6CuNO3 + Al2(SO4)3 → 3Cu2SO4 + 2Al(NO3)3
Molar mass of CuNO3 125.56 g/mol
Molar mass of Al(NO3)3 213.01 g/mol

How many grams of copper (I) nitrate (CuNO3) are required to produce 44.0 grams of aluminum nitrate (Al(NO3)3)?

Answers

Answer:

77.81 g of CuNO₃

Explanation:

6 CuNO₃  +  Al₂(SO₄)₃  ⇒  3 Cu₂SO₄  +  2 Al(NO₃)₃

This is your chemical equation.  We will need this information for converting from Al(NO₃)₃ to CuNO₃.

First, convert grams of Al(NO₃)₃ into moles using the molar mass.

[tex]44.0g*\frac{mol}{213.01g} = 0.2065mol[/tex]

Next, convert moles of Al(NO₃)₃ to moles of CuNO₃.  You can do this by using the stoichiometry (the numbers in front of the compounds).  For every 6 moles of CuNO₃, you will get 2 moles of Al(NO₃)₃, causing the ratio of CuNO₃ to Al(NO₃)₃ to be 6:2.

[tex]0.2065mol*\frac{6}{2} =0.6197mol[/tex]

Now that you moles of CuNO₃, convert this to grams using its molar mass.

[tex]0.6197 mol * \frac{125.56g}{mol} =77.81 g[/tex]

You will need 77.81 grams of CuNO₃ to produce 44.0 grams of Al(NO₃)₃.

a change of state does not affect an object's what.​

Answers

Answer:

Mass

Explanation:

True or False: The specialized cells in a UNICELLULAR organism perform
specialized jobs.
Your answer

Answers

The answer would be true

Answer:

True

Explanation:

Which example indicates that a chemical change has occurred? *
1 point
A. When two aqueous solutions are mixed, a precipitate is formed.
B. As ammonium nitrate dissolves in water causes the temperature to decrease.
C. Alcohol evaporates when left in an open container.
D. Water is added to blue copper(II) chloride solution. The resulting mixture if lighter blue in color.

Answers

Answer:

A. When two aqueous solutions are mixed, a precipitate is formed.

Explanation:

The precipitate (a solid substance that falls from the liquid) is the result of a chemical reaction taking place between the liquids.

The other three answer choices are indicative of physical changes (temperature change, phase change, color change).

When two aqueous solutions are mixed, a precipitate is formed indicates that a chemical change has occurred.  

Hence, option A is correct answer.

What is Chemical change ?

Chemical change are those changes in which substance changes chemical composition. These changes are permanent changes. In chemical change new substances formed and in chemical change substances can not get back into its original form. It is irreversible change.

What is Physical change ?

Physical changes are those changes in which substance changes physical properties only. Properties like temperature, pressure, shape, color, size, state (solid, liquid and gas). These changes are temporary in nature. In physical change no new substances formed. It is reversible change.

Now, check all the options one by one:

Option (A): When two aqueous solutions are mixed, a precipitate is formed is a chemical change. Since precipitation indicate a chemical reaction (that is double displacement reaction).

Option (B): As ammonium nitrate dissolved in water causes the temperature to decrease is a physical change because heat energy is absorbed here and it is a endothermic reaction.

Option (C): Alcohol evaporates when left in an open container is a physical change because evaporation is a physical change as it changes the state from liquid state to gas state.

Option (D): Water is added to blue copper (II) chloride solution. The resulting mixture if lighter blue in color is a physical change as properties like change in color is physical change.  

Thus, from above conclusion we can say that When two aqueous solutions are mixed, a precipitate is formed indicates that a chemical change has occurred.  

Hence, option A is correct answer.

Learn more about physical and chemical change here: https://brainly.com/question/17166994

#SPJ2

What is the molar mass of AIC13?

Answers

Aluminum Chloride = 133.34 g/mol

Which element best conducts electricity?
argon
copper
nitrogen
oxygen

Answers

Answer:

I think it is copper

Explanation:

.........................

Answer:

copper

Explanation:

how many atoms are in 4.67 grams of sample of silicon

Answers

2.33 is the right answer.

I NEED AWNSER ASAP What forms as a result of the wind's frictional force on water?


deep sea currents that move in a path opposite to the wind currents


surface currents that move in a path similar to the wind currents


surface currents that move in a path opposite to the wind currents


deep sea currents that move in a path similar to the wind currents (the sub is science)

Answers

Answer:

2 no. is the answer surface currents that move in a path opposite to the wind currents

Answer:

no.2 is the answer of your question

hi, if your looking for extra points (50+) and brainiest here is ur chance, answer this question correctly plz

Answers

Answer:

Answer is B

Explanation:

It's not A because we're boiling only water.

It's not C because the last dot for 2 cups ends at 70 min while the last dot for 4 cups ends at 90 min.

It's not D because water boils at around 100 C, as shown in the graph. The highest dot for both 2 cups and 4 cups were about the same near 100 C.

The graph shows that 4 cups of water is able to retain heat more (higher heat capacity), so it takes more time for water to cool down than 2 cups of water.

AWNSER FAST PLEASE
Based on the chemical equation, use the drop-down menu to choose the coefficients that will balance the chemical equation:
(awnsers H²O -> (awnsers H² -> (awnsers O²

awnser for all drop-down menus 1,2, or 3​

Answers

Answer: The coefficients are 2, 2 and 1.

Explanation: According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants.

The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.

The balanced chemical equation for the given reaction is:

2H2o➡️2h2+o2

Please help me thanks

Answers

Answer:

your finger becomes negatively charged

Explanation:

hope it helps. follow me

who are called anthropologist? ​

Answers

Answer: A person engaged in the practice of anthropology. Anthropology is the study of aspects of humans within past and present societies. Social anthropology, cultural anthropology and philosophical anthropology study the norms and values of societies.

Explanation: I HOPE THIS HELPS U AND ANSWERS UR QUESTION!!! Stay safe and healthy!

While performing a neutralization reaction, Jonna added 27.55 mL of 0.144 M H2SO4 to 43.84 mL of 0.316 M KOH. How many moles of OH- are unreacted in the solution after the neutralization is complete?

Answers

Answer:

5.916x10⁻³ mol OH⁻

Explanation:

The reaction that takes place is:

H₂SO₄ + 2KOH → K₂SO₄ + 2H₂O

First we calculate the added moles of each reagent, using the given volumes and concentrations:

H₂SO₄ ⇒ 0.144 M * 27.55 mL = 3.967 mmol H₂SO₄KOH ⇒ 0.316 M * 43.84 mL = 13.85 mmol KOH

Now we calculate how many KOH moles reacted with 3.967 mmol H₂SO₄:

3.967 mmol H₂SO₄ * [tex]\frac{2mmolKOH}{1mmolH_2SO_4}[/tex] = 7.934 mmol KOH

Finally we calculate how many OH⁻ moles remained after the reaction

13.85 mmol - 7.934 mmol = 5.916 mmol OH⁻5.916 mmol / 1000 = 5.916x10⁻³ mol OH⁻

What is the molar mass of H2CO3?
(Molar mass of H = 1.0079 g/mol; C = 12.010 g/mol; O = 15.999 g/mol)

Answers

Answer:

molar mass of H2CO3 = 72.0228

Answer:

62.02 g/mol

Explanation:

Took the test and got it right. if you have enough faith in brainly youll choose the right answer

which property is a property of water

Answers

Answer: Polarity, Boiling and Freezing Points, Specific Heat Capacity, Density, Surface Tension, Heat of Vaporization and Vapor Pressure, Capillary Action, Solid State (Ice), Liquid State (Liquid Water), Gas State (Steam),  

Explanation:  Water molecules are polar, so they form hydrogen bonds. This gives water unique properties, such as a relatively high boiling point, high specific heat, cohesion, adhesion, and density.

Calculate the molarity of 29.25 grams of NaCI in 2.0 liters of solution

Answers

Answer:

[NaCl(aq)] = 0.25M

Explanation:

Molarity = moles solute / volume of solution in liters

moles NaCl in 29.25 grams = 29.25g/58g·mol⁻¹ = 0.5043 mole

Molarity = 0.5043 mole NaCl / 2 Liters = 0.2555M ≅ 0.25M (2 sig-figs)

How many moles of KBr are present in 500 ml of a 0.8 M KBr solution?

1. 1.6
2. .4
3. .625
4. 625
5. .0016​

Answers

Answer:

2) 0.4 mol

Explanation:

Step 1: Given data

Volume of the solution (V): 500 mLMolar concentration of the solution (M): 0.8 M = 0.8 mol/L

Step 2: Convert "V" to L

We will use the conversion factor 1 L = 1000 mL.

500 mL × 1 L/1000 mL = 0.500 L

Step 3: Calculate the moles of KBr (solute)

The molarity is the quotient between the moles of solute (n) and the liters of solution.

M = n/V

n = M × V

n = 0.8 mol/L × 0.500 L = 0.4 mol

Which of the following statements best describes a
mixture?
O A substance that contains two or more elements chemically joined
O A substance that contains two or more elements not chemically joined
O A substance that contains only one type of atom
O A substance that contains two or more compounds or elements that are
not chemically joined.​

Answers

The last one. A mixture isn’t chemically combined.

need help whoever answers will be awarded branliest answer ​

Answers

Answer:

1.used to seperate solids from liquids, and is a act of pouring a mixture onto a membrane this allows the passage of liquid and results in the collection of a solid

2. the solution would passed through without losing and solids

3 would allow them to dry or on further hearing decompose

Explanation:

a furnace is thermal energy

A. True
B. False

Answers

Answer: true

Explanation:

Thermal efficiency of process heating equipment

A. True
It is thermal energy because it is used to heat air which it’s forced into system of ducts and registers.

PLEASE HELP IMMEDIATE WORTH 10 POINTS

Fill in the blank with the word or phrase that best completes the statement or answers the question. The scientific name for a plant that reproduces with flowers is a(n)​

Answers

Answer:

the scientific name is Angiosperms

Explanation:

please mark brainliest

The percent composition by mass of nitrogen in NH OH (gram-formula mass = 35 grams/mole) is equal to

Answers

Answer:

the percentage composition of mass of nitrogen in NH OH is 42.86 %

How many grams of AlCl3 will be produced if 3.85 moles of Al react? Al + ___Cl2 → ___AlCl3

Answers

Answer:

513.975g

Explanation:

I'm assuming that the question has Aluminium and Chlorine as the question is not clear.

1. Balance the equation

  2 Al + 3 Cl2  → 2AlCl3

2. Use the mole = mass/mr equation and molar ratio to find the mass of AlCl3

   133.5 x 3.85 = 513.975g

Mario’s teacher asked him to explain the important role of the sun in the water cycle. Which response would be correct?

Answers

it evaporate water and make it go back into the air or sky and start the whole circle all over

Match these items.

1. bring blood to the heart .veins
2. major artery bringing blood from the heart to the body .ventricle
3. doorways to the heart .aorta
4. measure of the rate of heart contractions .pulse
5. heart passageway to the arteries. valve
6. passage to the ventricle .atrium

Answers

Answer:

1- veins

2-aorta

3-valve

4-ventricles

5-atrium

A force of 10 N pulls an object to the right, and a force of 7 N pulls to the left, what is the net force

Answers

Answer:

2 N

Explanation:

A granulated cylinder was filled to 30.0 mL with liquid. An unknown metal cylinder having a mass of 60.27 g was submerged in the liquid. The final volume of the liquid level was 45.2 mL.

Answers

Answer:

Explanation:

A graduated cylinder was filled to 30.0 mL with a liquid. An unknown metal cylinder having a mass of 60.27 g was submerged in the in the liquid. The final volume of the liquid level was 45.2 mL.

a. Calculate the density of the unknown metal cylinder.

b. The density of the liquid is 0.899 g/mL. What is the mass of the liquid in the graduated cylinder?

The face-centered cubic unit cell describing the structure of an ionic compound has an edge length of 207 pm. The lattice points of the unit cell are occupied by anions, and the cations are small enough so that the anions are in contact along the diagonal of the face of the unit cell. What is the ionic radius of the anion (in picometers)

Answers

Answer:

73.2 pm

Explanation:

"The anions make contact along the diagonal of the face of the unit cell, so the diagonal of the face is equal to 4 ionic anion radii. By letting r represent the ionic radius of the anion, d represent the diagonal of the face of the unit cell, and x represent the edge length, then d=4r and

d^2=x^2+x^2=  2x^2

By substituting 4r for d, the second equation becomes

(4r)^2=(2)x^2

Solving this equation for r shows that

r=(x–√2)/4

Since the edge length x is 207 pm, the ionic radius of the anion is

r= ((207 pm) X [tex]\sqrt{2}[/tex])/4=73.2 pm

Notice that the formulae used to describe atomic radii include constants with exact values. Therefore, these values do not constrain the number of significant figures."

The ionic radius of the anion in the FCC unit cell where anions are in contact along the diagonal of the face of the unit cell is 73.1pm.

What is ionic radius?

Ionic radius is the distance between the center of the atom and the outermost part.

As in the question it is given that anions are in contact along the diagonal of the face of the unit cell, so the length of the diagonal is represented as: d = 4r, where

r = ionic radius

Length of edge i.e. a = 207 pm (given)

Two adjacent edges and diagonal of a FCC unit cell makes a right angle triangle, by using pythagoras theorem we can write as:

a² + a² = d²

2a² = (4r)²

2a²/16 = r²

2(207)²/16 = r²

85,698/16 =  r²

0r r = 73.18 pm

Hence, 73.18 pm is the ionic radius of the anion.

To learn more about ionic radius, visit the below link:

https://brainly.com/question/8137711

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