Classify each of the observed changes according to whether or not they are likely to represent evidence that a chemical reaction is occurring when performing an experiment.
May be evidence of a chemical reaction Not evidence of a chemical reaction
a solution color becoming less intense
due to dilution
bubbles (sas formation) changes in color
precipitation
explosion or fire
Answer Bank
a solid liquifying change in temperature solution colors mixing

Answers

Answer 1

Answer:

a solution color becoming less intense  due to dilution- is not an evidence of a chemical reaction

bubbles (gas formation) - evidence of a chemical reaction

explosion or fire - evidence of a chemical reaction

changes in color- evidence of a chemical reaction

precipitation- evidence of a chemical reaction

changes in temperature - evidence of a chemical reaction

a solid liquifying - is not an evidence of a chemical reaction

solution colors mixing - is not an evidence of a chemical reaction

Explanation:

A chemical change is not easily reversible and yields new substances. It is often accompanied by a loss or gain of heat.

In the answer section, i have shown some evidences that lead us to conclude that a chemical reaction has taken place. The occurrence of a chemical change often goes with the formation of new substances as earlier stated and any of these signs may accompany the process.

For instance, when a metal is dropped in dilute acid solution, bubble of hydrogen gas indicates that a chemical reaction has taken place.


Related Questions

Why do different places on Earth have different climates?

Answers

Answer:

cause of the sun rotation

Explanation:

Answer:

The world is tilting on an edge that creates seasons.

Explanation:

And that's why different parts of the have different climates.

What kind of intermolecular forces act between a hydrogen cyanide molecule and a potassium cation?
If there is more than one type of intermolecular force that acts, be sure to list them all, with a comma between the name of each force.
(dipole, hydrogen-bonding, dispersion, ion-dipole)

Answers

Answer:

ion-dipole

Explanation:

Let us remember that the potassium cation is an ion, a positive ion to be precise.

There is a dipole existing in the hydrogen cyanide molecule. The positive end of the dipole is on hydrogen while the negative end of the dipole is on the cyanide moiety.

The only possible interaction between the potassium cation and the hydrogen cyanide is an ion dipole interaction. The cation interacts with the cyanide moiety having a partial negative charge in the molecule.

Crude oil has many applications once it has been distilled at a refinery. According to the diagram, what process is used to distill crude oil into its various components to use energy distribution?

A) separation by density

B) separation by boiling points

C) separation by the porosity of the components

D) separation by the organic content or each component

Answers

Answer:

B) separation by boiling points

Explanation:

According to the diagram depicted, crude oil is separated into its different units using boiling points.

The boiling points of a compound is the temperature at which it begins to boil. The process of fractional distillation is used in the oil industry to separate crude oil into its components. When the boiling point of a oil fraction is reached, it becomes vaporized and rises within the column

Anyone Free can help me with this question please ?

Answers

Answer:

68

Explanation:

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Which compound has the greatest molecular mass?

CO2

H2O

Pb2

NH4

Answers

Pb2 has the greatest molecular mass

Anyone Can help me this question ‍♂️ please ?

Answers

Answer:

54.66 liters

Explanation:

First of all, remember this. 1 mole equals 22.4 liters.

Second of all, to show your work use dimensional analysis.

Write 2.44 moles and then put moles on the bottom and liters on top.

2.44 moles of O * 22.4 liters / 1 mol of O

Moles will cancel out.

2.44 x 22.4 = 54.656

Usually I would have used sig figs. But the question said to round your answer to two digits after the decimal point.

54.656 rounds to the hundreths place.

So 54.656 = 54.66

All in all, the final answer is 54.66 liters(don't forget the units).

Hope it helped!

I need help. Please help with the best of your ability.​

Answers

Answer:

Photosynthesis transforms light energy into chemical energy by making sugars. Cellular respiration releases the chemical energy from food by breaking down sugars.

Explanation:

I'm actually learning this in school right now

Hope this helps!

~PurpleMist

A student working in the laboratory produces 6.81 grams of calcium oxide, CaO, from 20.7 grams of calcium
carbonate, CaCO3, according to the reaction CaCO3 → CaO + CO2. Calculate the theoretical yield and
the percent yield for the reaction. Show and/or explain your work.

Answers

Answer:

A. Theoretical yield of CaO is 11.59 g

B. Percentage yield of CaO = 58.76%

Explanation:

The following data were obtained from the question:

Mass of CaCO₃ = 20.7 g

Actual yield of CaO = 6.81 g

Theoretical yield of CaO =?

Percentage yield of CaO =?

The equation for the reaction is given below:

CaCO₃ —> CaO + CO₂

Next, we shall determine the mass of CaCO₃ that decomposed and the mass of CaO produced from the balanced equation. This can be obtained as follow:

Molar mass of CaCO₃ = 40 + 12 + (3×16)

= 40 + 12 + 48

= 100 g/mol

Mass of CaCO₃ from the balanced equation = 1 × 100 = 100 g

Molar mass of CaO = 40 + 16 = 56 g/mol

Mass of CaO from the balanced equation = 1 × 56 = 56 g

SUMMARY:

From the balanced equation above,

100 g of CaCO₃ decomposed to produce 56 g of CaO.

A. Determination of the theoretical yield of CaO.

From the balanced equation above,

100 g of CaCO₃ decomposed to produce 56 g of CaO.

Therefore, 20.7 g of CaCO₃ will decompose to produce =

(20.7 × 56)/100 = 11.59 g of CaO.

Thus, the theoretical yield of CaO is 11.59 g

B. Determination of the percentage yield.

Actual yield of CaO = 6.81 g

Theoretical yield of CaO = 11.59 g

Percentage yield of CaO =?

Percentage yield = Actual yield /Theoretical yield × 100

Percentage yield = 6.81/11.59 × 100

Percentage yield of CaO = 58.76%

Shivani measures out 6.0 moles of epsom salt (MgSO) to put her bath. How many grams MgSO4 went in the bath?

Answers

Answer: 720 g

Explanation:

To solve this we must be knowing each and every concept related to mole. Therefore, shivani measures out 6.0 moles of epsom salt (MgSO[tex]_4[/tex]) to put her bath. 1,566g MgSO[tex]_4[/tex] went in the bath.

What is mole?

A mole is merely a measuring unit. In reality, it is one of its International System of Units' seven foundation units. When current units are insufficient, new units are created.

Chemical reactions frequently occur at levels where employing grams would be inappropriate, but using absolute quantities of atoms/molecules/ions would also be misleading.

For all practical reasons, one mole of a substance in grams is nearly equal to 1 molecule for the compound per daltons.

Mathematically,

number of mole =given mass ÷ molar mass

number of mole=6.0 moles

molar mass of epsom= 261.47g/mol

substituting all the given values in the above equation, we get

6.0 moles =mass of epsom ÷ 261.47g/mol

mass of epsom =1,566g

Therefore, 1,566g  MgSO[tex]_4[/tex] went in the bath.

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What is the relationship between the mass of the boat and the mass of the displaced
liquid?

Answers

Answer: The mass of the displaced liquid is equal to the volume of the liquid multiplied by its density. When a boat is placed in water, the volume of displaced water is equal to the mass of the boat.

I hope this helped!

The mass of the boat is equal to the mass of the liquid which is displaced by placing the boat in the liquid.

What is Archimedes' Principle?

Archimedes' Principle states that the buoyant force of the object is equal to the weight of the water which is displaced by the boat. If the weight of the water that is displaced by the boat is less than that of the weight of the boat, then in this case the boat sinks. Archimedes' principle or the buoyant force is very useful for the calculation of the volume of an object that does not have a regular shape.

The mass of the displaced liquid is always equal to the volume of the liquid multiplied by the density of the fluid. When a boat is placed in the water, the volume of displaced water is equal to the mass of the boat which is placed in it.

Learn more about Displacement here:

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write few lines about luis braille

Answers

Answer:

Louis braille was a french educator and inventor of a sytem of reading and writing for use use by the blind or visually impaired . his system remains virtually unchanged to this day and is know worldwide simply as braille

How many moles are in 56.4 grams of AlF3

Answers

Answer: 0.671614483912211

Explanation: A mole is 6.02214076×1023 (also known as the Avogadro number) I hope this helps!

How did the grandmother show her gratitude towards her granddaughter
answer this and in end please tell me how to mark answer as brainliest I will mark your answers as brainliest​

Answers

Answer:

vgffffgggggvghvxgyfdgubvhumigrrdghg

what element has greatest atomic radius from group 3?

Answers

Answer:

i think iron

Explanation:

i not sure with my ans

FUСR THE WORLD SAY AND TO 4142-414=? HELPPPPPPPPPPPPP

Answers

Answer:

UMMMMMMMMMMM

Explanation:

Answer:

3729

Explanation:

Construct an explanation using Newton's Laws of Motion to describe the effects of balanced and unbalanced forces on the motion of an object.

Answers

Answer:

The manner in which objects will move is determined by the answer to this question. Unbalanced forces will cause objects to change their state of motion

Explanation:

Since these two forces are of equal magnitude and in opposite directions, they balance each other.

Answer:

balance force are those force whose resultant force is zero and unbalanced force are those whose resultant are non zero

A1(OH)3 + HNO3–> H2O + A1(NO3)3

when the equation above is correctly balanced the coefficient of H2O is

A:1
B:2
C:3
D:8

Answers

Answer:

3

Explanation:

The reaction expression is given as:

      Al(OH)₃  +   HNO₃   →    H₂O   +  Al(NO₃)₃  

To solve this problem, let us assign coefficient a,b,c and d to each specie;

           aAl(OH)₃  +   bHNO₃   →    cH₂O   +  dAl(NO₃)₃  

Conserving Al : a  = d

                   O:  3a + 3b  = c + 9d

                   H: 3a + b  = 2c

                   N: b  = 3d

let a = 1 , d  = 1, b  = 3 , c = 3

  Multiply through by 3;

 a  = 1, b  = 3, c = 3 and d  = 1

   Al(OH)₃  +   3HNO₃   →    3H₂O   +  Al(NO₃)₃  

Which of the following is not a natural
way water is stored in the water cycle?
A Stream
B. Pond
C. Iceberg
D. Cup

Answers

Answer:

cup...................

Yes it is definitely D: Cup

how does the disturbance travel through the coil when you move your arm back and forth?

Answers

Answer:

The waves travel in a direction parallel to direction of the vibration of the medium

The waves travel in a direction parallel to direction of the vibration of the medium

what is mechanical wave ?

A mechanical wave is defined as an oscillation of matter which is responsible for energy transfer via  medium.

The propagation of  wave is limited by the medium of transmission, the oscillating material which revolve around a fixed point with little translational motion.

A surface wave which is an example of  mechanical wave that propagate  along the interface of two different media in physics. other common examples are Gravity waves on the surface of liquids, ocean waves.

Surface wave can be propagated in a slow way through Earth material and are generally lower in frequency than body waves.

For more details regarding wave, visit

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Express 4,935,000 using standard scientific notation

Answers

Answer:

4.935×10-1

Explanation:

Take away the 0

Which of the below elements are part of a group? Feel free to use the periodic table.

A. H, He, O, C

B. Be, Mg, Ca, Sr

C. Li, Be, C, O

D. H, Li, Na, Mg

Answers

B. Be, Mg, Ca, Sr (hope this helps)

Answer:

B. Be, Mg, Ca, Sr

Explanation:

Be, Mg, Ca, Sr are parts of the alkaline Earth metal family/group. So they are the second most reactive elements following behind alkali metals. Furthermore, Be, Mg, Ca, Sr all have 2 valence electrons that lose them to form cations. They have low melting points, low boiling points, can conduct electricity, have high malleability and ductility.

Hope it helped!

what molecules must the plant take in so the process of photosynthesis can occur

Answers

Answer:

Glucose molecules

Explanation:

1. What are the two effects of the continental plate/continental plate convergent boundary?

2. Where can you find an example of this type of divergent boundary? Which country, continent or ocean?

Answers

Answer

oh you again?

Explanation:

what three things might influence a slide when conditions are right? ​

Answers

Answer:

3

Explanation:

The three things that can affect a condition to enforce a slide is friction, weight, and slope of an area. Solutions that can make flow easily are those that can create less friction depending on the condition of an environment where it is present.

The table below shows properties of two compounds at standard pressure. Which statement classifies the two compounds? 1)Both compounds are ionic, 2)Both compounds are molecular, 3) Compound 1 is ionic, and compound 2 is molecular, 4)Compound 1 is molecular, and compound is ionic

Answers

Answer:

3) Compound 1 is ionic, and compound 2 is molecular

Explanation:

Compound-1 is an ionic compound while Compound-2 is a molecular compound. Option 3 is correct.

Ionic Compound:

They are formed when an atom donates its electron to another atom. This results in one positive and one negative ion.

Hence, it is a very strong bond. These compounds have a very high melting and boiling point. They are very good electric conductors in the aqueous solution.

For example- NaCl.

Molecular compounds:

They are compounds that are made up of discrete molecular units. For example- [tex]\bold {H_2O}[/tex]

They have very weak intermolecular bonds hence have low boiling and melting point and do not conduct electricity.

SInce Compound-1 has higher MP and BP and Compound-2 has low melting and boiling point.

Therefore, Compound-1 is an ionic compound while Compound-2 is a molecular compound.

To know more about Ionic Compound:

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A mixture is made by combining 1.61 lb of salt and 5.37 lb of water. What is the percentage of salt (by mass) in this mixture?

Answers

Answer:

Hey okau

Explanation:

X/100% = part / whole

X/100% = 1.62 / (1.62 + 4.81) = 0.252

X = 25.2%

Sodium chlorite decomposes into salt and oxygen gas. What is the correct balanced decomposition reaction.
NaClO3 -> NaCl + O2

Answers

Answer:

i think it would be c

Explanation:

sorry if it is wrong

Answer:

2NaClO₃ -> 2NaCl + 3O₂

Explanation:

The number of atoms in the reactants has to equal the number of atoms in the products.

Hope that helps.

7.
Use the reaction below for the reaction of dicyanoacetylene with
ozone to produce carbon monoxide and nitrogen.
3C4N2(8) + 403(g) → 1200(8) + 3N2(g).
What volume of CO is produced when 1.20 L of C4N2 reacts?
a 0.300 L CO
b 3.60 L CO
C 14.4 L CO
d 4.80 L CO

Answers

Answer:

D

Explanation:

The volume of carbon monoxide is produced when 1.20 L of dicyanoacetylene reacts is

What is stoichiometry?

Stoichiometry of any reaction tells about rhe relative amount of substance present before and after the completion of any chemical reaction.

Given balanced chemical reaction between dicyanoacetylene and ozone to produce carbon monoxide and nitrogen is:

3C₄N₂ + 4O₃ → 12CO + 3N₂

From the stoichiometry of the reaction it is clear that:
3 liters of C₄N₂ =  produces 12 liters of CO

1.20 liters of C₄N₂ =  produces 12/3×1.20=4.8 liters of CO

Hence option (d) is correct i.e. 4.8 liters.

To know more about stoichiometry, visit the below link:
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PLZ HELP BEING TIMED!!!!!PLZ ANSWER!!!!

Answers

Answer:

1st one

Explanation:

Complete the chemical equation and name the type of reaction taking place.

In the problem below, the ions have the following charges: Γ-2 and φ-2

H2Γ + φ(OH)2 -->

PLEASE HELP

Answers

I think it would be 2
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