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

8. How many moles of carbon dioxide are there in 52.06 g of carbon dioxide?
A) 0.8452
B) 1.183
C) 6.022 x 1023
D) 8.648 x 1023
E) 3.134 x 1025

Answers

Answer:

B) 1.183

Explanation:

To convert from grams (mass) to moles, we need to divide by the atomic mass (amu)..

The amu of [tex]CO_{2}[/tex]  is 44.008

52.06/44.08 = 1.182966733

This can be rounded to 1.1830 moles of CO2

1.183 moles of carbon dioxide are there in 52.06 g of carbon dioxide.

Explanation:

Moles of substance are defined ratio of the given mass of the substance to the molar mass of the substance.

Given :

The 52.06 grams of carbon dioxide.

To find :

The moles of carbon dioxide.

Solution:

The mass of carbon dioxide = 52.06 g

The molar mass of carbon dioxide = 44.01 g/mol

The moles of carbon dioxide:

[tex]=\frac{52.06 g}{44.01 g/mol}=1.183 mol[/tex]

1.183 moles of carbon dioxide are there in 52.06 g of carbon dioxide.

Learn more about the number of moles here:

brainly.com/question/16192776?referrer=searchResults

brainly.com/question/2293228?referrer=searchResults

To convert between units, you need to know the relationship between units. For example, one mile equals 5280 feet. This relationship can now be used as a conversion factor, set up as required by the question. For each conversion, choose the correct arrangement of the conversion factor and complete the calculation 1. Convert 7860 feet to miles 7860 feet x (A)
A: 1 mile
B: 5280 feet 7860 feet miles 2. Co 0.5 miles to feet 0.565 miles x (C) TD
C: Choose...
D: Choose 0.565 miles feet

Answers

Answer:

1. 7860 Feet = 1.488 miles

A= 1

B= 5280

2. 0.565 miles = 2983.2 feet

C= 0.565

D= 1

Explanation:

1. Convert 7860 feet to miles

1 miles= 5280 feet

1 Feet= 1/ 5280 miles

7860 Feet= 7860 ( 1/ 5280) miles

7860 Feet = 1.488 miles

A= 1

B= 5280

2. Convert 0.565 miles to feet

1 mile= 5280 feet

0.565 miles = 5280 feet * (0.565/1)

0.565 miles = 2983.2 feet

C= 0.565

D= 1

We see that when we have to convert feet into miles we divide the number by 5280 because feet are smaller than miles. Similarly when we have to convert miles into feet we multiply by the given number because miles are greater than feet.

The above method used is called the unitary method but we should always keep in mind that conversion from smaller to bigger units require divsion and from bigger to smaller units require multiplication.

HELPPPPPPPPPPPPPPPPPP

Answers

Answer:

*helps and doesnt get deleted*

Explanation:

Jill graphs the speed of a model train that is travelling at a speed of 15 kilometers per hour. Which graph shows the speed of the model train?

Answers

Answer:c

Explanation:

What type of crust is colliding?
Japan Trench
Eurasian Plate
Pacific Plate

Answers

Answer: The Eurasian Plate or both the Eurasian and Pacific Plate.

Explanation:

What are the names of the compounds containing silver?
Show the compound formula and their names. (WRITE CLEARLY AND NEATLY OR THE QUESTION WILL BE CONSIDERED WRONG)

Answers

Answer:

the silver compounds include:

silver chloride agcl ,

silver bromide agbr ,

and silver iodide agi.

A(n)_________contains only one type of atom, whereas a(n)_________ is composed of two or more different elements bonded together. A(n)___________ also contains more than one substance, but these can be separated by physical means, whereas the components of a compound cannot.

Answers

Answer:

1. Element

2. Compound

3. Mixture

Explanation:

Elements and compounds are both pure substances. ELEMENTS are substances that contain only one type of atom. For example, Cl2 contains only chlorine atoms. COMPOUNDS, on the other hand, contain atoms of two or more elements that are chemically joined together. For example, CaCl2 contains atoms of calcium and chlorine.

MIXTURES are another kind of substances that contains more than one substances, however, unlike compounds, they are not chemically joined. Mixtures can easily be separated by physical means.

Sulfur dioxide (SO2) is an unwelcome result
of burning soft coal in power plants. Some
of the SO2 ends up as sulfuric acid in acid
precipitation. The net reaction is
2 SO2(g) + O2(g) + 2 H2O(l) —— 2 H2SO4(l)
What mass in grams of SO2 is needed to
react with 1771 g of O2?
Answer in units of g.

Answers

Answer:

I believe it is 1771 divided by 4

Explanation:

Suppose your metal sample is hammered into the shape of a thin coin with a diameter of 8.62 cm. Determine the thickness (in mm) of this metal sheet. Use the measured metal mass and true denisty of your metal for this calculation.
measured metal mass: 83.956 g
true density: 8.90 g/cm3

Answers

Answer:

The thickness of the metal sheet is 0.162 centimeters.

Explanation:

If mass within the coin is uniformly distributed, then the density ([tex]\rho[/tex]), measured in grams per cubic centimeter, can be represented by the following formula:

[tex]\rho = \frac{m}{\frac{\pi}{4}\cdot D^{2}\cdot z }[/tex] (1)

Where:

[tex]m[/tex] - Mass, measured in grams.

[tex]D[/tex] - Diameter, measured in centimeters.

[tex]z[/tex] - Thickness, measured in centimeters.

If we know that [tex]m = 83.956\,g[/tex], [tex]D = 8.62\,cm[/tex] and [tex]\rho = 8.90\,\frac{g}{cm^{3}}[/tex], then the thickness of the coin is:

[tex]z = \frac{m}{\frac{\pi}{4}\cdot D^{2}\cdot \rho }[/tex]

[tex]z = \frac{83.956\,g}{\frac{\pi}{4}\cdot (8.62\,cm)^{2}\cdot \left(8.90\,\frac{g}{cm^{3}} \right) }[/tex]

[tex]z = 0.162\,cm[/tex]

The thickness of the metal sheet is 0.162 centimeters.

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

Answers

Answer:

UMMMMMMMMMMM

Explanation:

Answer:

3729

Explanation:

Which change of state involves a release of energy?

Answers

Answer: CONDENSATION When steam is cooled, it releases thermal energy and turns into its liquid state. This process is called condensation. reversed if the liquid is cooled. The change from the liquid state to the solid state is called freezing

PLZ HELP ME BEING TIMED!!!!!

Answers

Number 3! Good luck!

What is creating our Earth's Magnetic field?
1) Our Earth's iron liquid outer core rotating around the solid inner core
2) Our Earth having a stationary inner core
3) Our Earth having rocky center
4) All of the above

Answers

Answer:

1) Our Earth's iron liquid outer core rotating around the solid inner core

Explanation:

The earth's magnetic field or the geomagnetic field is produced as a result of the earth's iron liquid outer core rotating around the solid inner core.

This produces the earth's magnetic field.

The earth's core is made up of solid and liquid region. Only the densest elements are found within this region. So, the core is made up of metals which are mainly iron and nickel. The outer core is liquid or molten iron and the inner core is solid. The molten iron and nickel in the outer core moves around the inner core and generates the currents which induces a magnetic field round the earth.

Select the correct balanced equation for the double displacement reaction of calcium carbonate and hydrochloric
acid (Rolaids and stomach acid)
CaCO3 + HCL -> CaCl2 + H2CO3

Answers

Answer:

B: CaCO3 + 2HCl -> CaCl2 + H2CO3

Explanation:

CaCO3 + HCl -> CaCl2 + H2CO3

Count how many elements they are in all molecules for the reactants and for the products.

For the reactants:

Ca = 1 element

C = 1 element

O = 3 elements

H = 1 element

Cl = 1 element

For the products:

Ca = 1 element

Cl = 2 elements

H = 2 elements

C = 1 element

O = 3 elements

To balance this equation, we need to add 1 more element of Chlorine and Hydrogen.  Therefore, we add a 2 to the coefficient of HCl for the reactants side.

Now let us try it.

CaCO3 + 2HCl -> CaCl2 + H2CO3

Count how many elements they are in all molecules for the reactants and products.

For the reactants:

Ca = 1 element

C = 1 element

O = 3 elements

H = 2 element

Cl = 2 element

For the products:

Ca = 1 element

Cl = 2 elements

H = 2 elements

C = 1 element

O = 3 elements

All of the elements are balanced.

So the final answer is B: CaCO3 + 2HCl -> CaCl2 + H2CO3

Hope it helped!

A parallel circuit contains four identical lamps. The current through the energy source is 4 A. The total resistance of the circuit is 10 Ω. What is the voltage across the energy source and across each lamp

Answers

Answer:

a parallel circuit has two or more paths for current to flow through voltage is the same across each component of the parallel circuit the sum of the current through each path is equal to the total current that follows from the source another definition is in a parallel circuit all components are connected across each other formally exactly two sets of electricity common points a branch in a parallel circuit in a path of electricity current formed by one of the load component

The following chemical reaction takes place in aqueous solution:
AgF(aq)+Nal(aq) ——> Agl(s)+NaF(aq)
Write the net ionic equation for this reaction.

Answers

The net ionic equation : Ag⁺(aq)+l⁻(aq) ⇒ Agl(s)

Further explanation

Given

Reaction

AgF(aq)+Nal(aq) ——> Agl(s)+NaF(aq)

Required

The net ionic equation

Solution

The equation of a chemical reaction can be expressed in the equation of the ions

In the ion equation, there is a spectator ion that is the ion that does not react because it is present before and after the reaction  

When these ions are removed, the ionic equation is called the net ionic equation  

AgF(aq)+Nal(aq) ——> Agl(s)+NaF(aq)

Ag⁺(aq)+F⁻(aq)+Na⁺(aq)+l⁻(aq) ⇒ Agl(s)+Na⁺(aq) + F⁻(aq)

Ag⁺(aq)+l⁻(aq) ⇒ Agl(s)

Which chemical used to make explosives is a fertilizer-based explosive, but requires nitric acid as a component to be an explosive compound, and has a wide range of uses, including as a noncorrosive de-icing material for sidewalks?
a. Aluminum nitrate
b. Triacetone triperoxide (TATP)
c. Hexamethylene triperoxide diamine (HMTD)
d. Urea nitrate

Answers

Answer:

d. Urea nitrate

Explanation:

Urea nitrate is a fertilizer-based explosive that is produced in one step by reaction of urea with nitric acid. The is an exothermic reaction, therefore, necessary steps and precautions must be taken to ensure safety during the process. The equation of the reaction is given below:

(NH₂)₂CO (aq) + HNO₃ (aq) → (NH₂)₂COHNO₃ (s)

It is as easily-made explosive and can also be used as a catalyst in Diels-Alder reactions of aromatic amines.

In the presence of water, urea nitrate readily decomposes to its original components, urea and nitric acid.

On its own, urea  is commonly used as a deicer for sidewalks as it is a noncorrosive de-icing material. However, it is a more costly method of deicing,  compared to other methods and it is best used where water runs off into vegetation than into a water-body or a storm drain because of its high-oxygen demand which could result in its reducing the oxygen level of the water body. It It is readily found in nature (in our urine) and is also  synthesized artificially.  It has a very high nitrogen content, and is most often used as a nitrogen‐based fertilizer.

matter can undergo chemical reactions and nuclear reactions. which properly is conserved in nuclear reactions?​

Answers

Answer:change in number of atoms

Explanation:AP3X

Who first purpose the theory of continental drift

Answers

Answer:

The theory of continental drift is most associated with the scientist Alfred Wegener. In the early 20th century, Wegener published a paper explaining his theory that the continental landmasses were “drifting” across the Earth, sometimes plowing through oceans and into each other.

Explanation:

PLEASE MARK ME AS BRAINLIEST

Answer:

The scientist Alfred Wegener.

Explanation:

Elements on the periodic table are arranged?

Answers

Answer:

In atomic number

And size

And nature of each (metal, non, or metalloide)

[tex]\Large \boxed{\sf by \ their \ properties}[/tex]

Every element has a set of particular characteristics. Each has a unique atomic and mass number because they contain a different ratio of protons and neutrons. The number of protons in an element mirrors the element's atomic number. The mass number equals the sum of the element's protons and neutrons.

According to increasing atomic numbers, chemical elements get organized. Periods and groups are the names of the horizontal rows and vertical columns, respectively. The chemical characteristics of elements within the same group are comparable due to their similar valency and number of outer electrons.

What is the frequency of a photon that has a wavelength of 6.58 x 10-8m?

Answers

Answer:

6 x 10 (power to the 15) H2

Answer:

i dont know the answer but you could search up photon calculator, hope this helps (im very sorry i couldnt help but i havent learned about that yet, im in 9th grade)

Why does a circuit need to connect the negative to the positive sides of a battery?

Answers

If they didn’t do this then the circuit would not be complete and electricity needs a complete circuit to be effective

A certain solid element is better electrical conductor than sulfur, but a poorer electrical conductor than copper. Which of the following elements is most consistent with this information.
a) germanium b) oxygen c) potassium d) mercury e) neon

Answers

C is the awnser! :)))))

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.

What do most mollusks have?
C

Answers

Answer:

C- A foot

Particularly a muscular foot.

Answer/Explanation

you"re right they have a foot

Muscular foot for creeping or burrowing. Some also have a head with sense organs.

did u need someone to confirm it or what

6. What is the equilibrium constant for the following reaction?
C+02 = CO2

Answers

[tex]\tt Kc=\dfrac{[CO_2]}{[C][O_2]}[/tex]Further explanation

Given

Reaction

C+02 = CO2

Required

The equilibrium constant

Solution

The equilibrium constant is the ratio of concentration or pressure between the product and the reactant with each reaction coefficient raised  

The equilibrium constant is based on the concentration (Kc) in a reaction  

pA + qB -----> mC + nD  

[tex]\large {\boxed {\bold {Kc ~ = ~ \frac {[C] ^ m [D] ^ n} {[A] ^ p [B] ^ q}}}}[/tex]

So for the reaction :

C+O₂ ⇔ CO₂

[tex]\tt Kc=\dfrac{[CO_2]}{[C][O_2]}[/tex]

2 NaOH (s) + CO2(g) → Na2CO3 (s) + H20 (I) How many grams of water can be produced with 1.85 moles of NaOH​

Answers

Explanation:

Mole ratio of NaOH to H2O = 2 : 1

Moles of H2O = 1.85mol * (1/2) = 0.925mol.

Mass of H2O = 0.925mol * (18g/mol) = 16.65g.

Answer:

16.65 grams of water can be produced with 1.85 moles of NaOH.

Explanation:

Mole ratio of NaOH to H2O = 2 : 1

Number of moles of water = (1/2)×1.85= 0.925 moles

Molar mass of water (H2O) = 18g/mol

Mass of the right water = 18g/mol×0.925 mol=16.65 grams

How far in advance is weather forecasting most accurate?

one week
one month
multiple years
multiple months

Answers

Answer:

One week.

Explanation:

I would think one month because on weather websites you can see a month of weather. But the closer the day your looking at the prediction will be more accurate.

The most accurate range of data for weather forecasting is: A. one week.

What is weather?

Weather can be defined as the average atmospheric conditions of a particular area (region) over a short period of time.

The elements of weather.

Some examples of the elements of weather include the following:

PrecipitationAtmospheric pressureRelative humidityWind speedTemperature

In meteorology, the most common forecasted element of weather is temperature (degree of hotness or coldness) and it usually done a weekly basis such as one week.

Read more on weather here: https://brainly.com/question/24730207

What is the definition of an atmosphere? a portion of the electromagnetic spectrum that makes the sky look blue the blanket of gases that surrounds Earth and some other planets an area above Earth that scatters sunlight into all colors of the rainbow​

Answers

Answer:

the blanket of gases that surrounds Earth and some other planets

Explanation:

The best definition of the atmosphere is that it is a portion of the earth that is a made up of a blanket of gases.

The atmosphere is not peculiar to the earth alone, some other planets also have atmospheric cover. The earth's atmosphere is divided into many different layers. The weather we see and experience on the earth surface is conditioned within the troposphere. This troposphere is the closest layer to the surface.

An idea based on observations with no experimental evidence is a:

Answers

A Hypothesis.

I Hope This Helps! (^_^)
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