Which of the following best represents a ​chemical change?

A. Chopping wood
B. Silver tarnishing (changing color)
C. Grape kool-aid mix dissolving in water
D. Dry ice turning into a gas (sublimation- a change of state)

Answers

Answer 1

B. silver tarnishing


Related Questions

A team of scientists is conducting tests to measure the boiling point of a liquid using a thermometer in the liquid. The team is
then recording the temperature where the liquid changes from a liquid to a gas rapidly. After 100 trials, the results are 5 degrees
below the expected results. Which next step is most reasonable? (1 point)

O checking the calibration of the thermometer to ensure that it is giving accurate readings
O assuming that the new results are incorrect
O assuming that the previous measurements are incorrect
O checking the insulation of the apparatus to find out if heat is escaping

Answers

The most reasonable step to take will be to check the calibration of the

thermometer to ensure that it is giving accurate readings.

Experiments which are done to be give the same results under standard

conditions. Common causes of incorrect results during the analysis of

boiling point of substances include heating the substance too rapidly or

the thermometer not being properly calibrated.

The thermometer is used to measure the temperature and so must be

properly calibrated to give accurate readings.

Read more on https://brainly.com/question/24657998

If 0.45 mole oxygen gas occupies a volume of 1.5 L, what volumes will 2.0 moles of oxygen gas occupy at the same temperature and pressure?

please don't send YouT8ube link i need a solution

Answers

Answer:

1. How many moles of oxygen will occupy a volume of 2.5 liters at 1.2 atm and 25° C? PV = V (1.2 n. 0821) (298) = 123 mols 2.

2.0 moles of oxygen gas will occupy a volume of 6.67 L at the same temperature and pressure.

Moles is a unit of measurement used in chemistry to express the amount of a substance. It is a counting unit that represents the number of particles, such as atoms, molecules, or ions, in a given sample.

One mole of a substance is defined as the amount of that substance that contains Avogadro's number of particles, which is approximately 6.022 x 10²³. This number is based on the concept that atoms, molecules, and ions are extremely small and difficult to count individually, so using moles allows for a more practical and convenient representation of quantities.

Given:

Moles of oxygen gas (initial) = 0.45 mol

Volume of oxygen gas (initial) = 1.5 L

Moles of oxygen gas (final) = 2.0 mol

Volume of oxygen gas (final) = ?

Using the principle of molar volume, we can set up the following ratio:

(0.45 mol / 1.5 L) = (2.0 mol / V)

V = (1.5 L × 2.0 mol) / 0.45 mol

V = 6.67 L

Learn more about Moles, here:

https://brainly.com/question/26416088

#SPJ6

How do ionic and molecular compounds behave in water?

Answers

Ionic compounds dissolve in water by a process called dissociation. Water molecules separate the cations and ions by means of ion-dipole attractions to form hydrated ions.

Answer:

When ionic compounds dissolve in water they go through a process called dissociation, splitting into the ions that make them up. However, when you place covalent compounds in water, they typically do not dissolve but form a layer on top of the water.

a meter is defined as 100. cm. How many significant digits are there in the value

Answers

Answer:

3 significant figure

Explanation:

Trailing zeros in a number are significant ONLY is the number contains a decimal point.

So if it was 100cm with out the decimal point would only have 1 significant figure.

A solution that contains 3 grams of solute dissolved in 100 millimeters of solution is:
a) 3% m / m
b) 3% m / v
c) 10% m / v

Answers

Answer:

the answer is correct part another is a part

Explanation:

c part

Predict the decay process and write the nuclear equation of Cf- 255

Answers

Answer:

curium

243

,

252

/

99

Es,  

251

/

98

Cf,  

214

/

82

Pb

Explanation: Im not very good with this but here ya go!

What type of material is half-life associated with?

Answers

Answer:

Radioactive material

Explanation:

Why do thermistors increase in conductivity when heated? What happens in normal metals? Explain on the atomic level.

Answers

Metal conductivity generally goes down or resistivity goes up with temperature goes up.

How many moles of CH, are present in a 13982.87 gram sample of CHg?

Answers

Moles= mass/molar mass
=13982.87/(12+1)
= 1,075.605384615385 moles

Element X has an electron configuration of 2-8-2. This element will combine with the oxide ion to form a compound with the formula

Answers

2+8+2 = 12 electrons
Magnesium has 12 electrons
Magnesium and oxide combine to for Magnesium Oxide
Mg^2+ + O^2- = MgO

NEED HELP ASAP WILL GIVE BRAINLIEST

Answers

Answer:

First we know that the molar mass of CO2 is 44.01g/mol, and that the sample of CO2 contains 3.408 x 10^21 molecules, and we have to find the mass of that sample.

We know that moles = mass/molar mass, if we rearrange the equation for mass, we'll get:

mass = moles x molar mass

Also, note that the number of atoms/molecules in a sample is the moles of the sample x Avogadro's number (6.02 x 10^23)

If we rearrange the equation for moles, we would get:

moles = molecules of sample/6.02 x 10^23

Plug in the values for the equation above to get the moles:

moles = (3.408 x 10^21)/(6.02 x 10^23)

moles = 0.00566112956 (we're not done yet)

Now that we have the moles and we were already provided the molar mass, we can calculate the mass using the very first equation we rearranged.

mass = moles x molar mass

mass = 0.00566112956 x 44.01

mass = 0.2491g (answered 4 places past the decimal point)

Therefore the sample of Carbon Dioxide has a mass of 0.2491g

need answer asap ..
-20 points! asap please ..

Answers

Answer:

[tex][tex]\purple{\rule{45pt}{7pt}}\purple{\rule{45pt}{999999pt}}[tex][/tex]

Explanation:

[tex][tex]\purple{\rule{45pt}{7pt}}\purple{\rule{45pt}{999999pt}}[tex][/tex]

Ensure you write the states of the reactants and products.
• phosphoric acid reacts with magnesium hydroxide

Answers

H3PO4 (aq) + Mg(OH)2 (s) -> Mg3(PO4)2 (s) + H2O (l)


What is the molarity of a NaOH solution when 22.14 mL of 0.105 M oxalic acid is needed to
neutralize 25.0 mL of the base.

Answers

The molarity of the NaOH solution required for the reaction is 0.186 M

We'll begin by writing the balanced equation for the reaction

H₂C₂O₄ +2NaOH —> Na₂C₂O₄ + 2H₂O

From the balanced equation above,

The mole ratio of the acid, H₂C₂O₄ (nA) = 1

The mole ratio of the base, NaOH (nB) = 2

From the question given above, the following data were obtained:

Volume of the acid, H₂C₂O₄ (Va) = 22.14 mL

Molarity of the acid, H₂C₂O₄ (Ma) = 0.105 M

Volume of the base, NaOH (Vb) = 25 mL

Molarity of the base, NaOH (Mb) =?

MaVa / MbVb = nA/nB

(0.105 × 22.14) / (Mb × 25) = 1/2

2.3247 / (Mb × 25) = 1/2

Cross multiply

Mb × 25 = 2.3247 × 2

Mb × 25 = 4.6494

Divide both side by 25

Mb = 4.6494 / 25

Mb = 0.186 M

Therefore, the molarity of the base, NaOH solution is 0.186 M

Learn more: https://brainly.com/question/25739717

OOO OOO
Water's strong hydrogen bonds result in which physical properties? Check all that apply.
high boiling point
low boiling point
high specific heat
low specific heat
density of ice being less than that of liquid water
density of ice being greater than that of liquid water

Answers

Water has a low boiling point and density of ice is less than of liquid water


why compounds with weak molecular forces are usually gases.

Answers

Molecular substances tend to be gases because the intermolecular forces of attraction are comparatively weak. You don't have to break any covalent bonds in order to melt or boil a molecular substance.

The longest intermolecular separation and hence the strongest intermolecular pressure of attraction can be found in the gaseous state of matter.

Although solids' intermolecular interactions were sufficient to maintain themselves in locked places, gases often have weak intermolecular forces that cause them to remain considerably separated. The gases possess greater intermolecular space than solids as a result of these weak forces.

To know more about molecular forces:

https://brainly.com/question/21826959

#SPJ1


What makes the Earth go around the Sun?




Answers

Answer:

Just as the Moon orbits the Earth because of the pull of Earth's gravity, the Earth orbits the Sun because of the pull of the Sun's gravity. ... This happens because the Earth has a velocity in the direction perpendicular to the force of the Sun's pull.

Explanation:

AgNO3 is a useful chemical that has many applications and can undergo a variety of reactions. In the following examples, balance each equation if necessary and then identify what type of reaction it represents. i. AgNO3 + Cu —>Cu(NO3)2 + Ag ii. AgNO3 —> Ag +O2 + NO2 iii. AgNO3 + KCI —> AgCI + KNO3 iv. Ag+ +I- +Agl

Answers

The balance chemical equation and the type of reaction of AgNO₃ and the other compounds can be represented as follows;

2AgNO₃ + Cu → Cu(NO₃)₂ + 2Ag (single displacement )

2AgNO₃ → 2Ag + O₂ + 2NO₂ (decomposition reaction)

AgNO₃ + KCI → AgCI + KNO₃(double displacement reaction)

2Ag + I₂ → 2AgI (synthesis reaction)

AgNO₃ + Cu → Cu(NO₃)₂+ Ag

The balance equation is as follows:

2AgNO₃ + Cu → Cu(NO₃)₂ + 2Ag

This is a single displacement (substitution)  reaction. The Copper substance displaced silver from it compound.  

AgNO₃ → Ag + O₂ + NO₂

The balance equation is represented as follows:

2AgNO₃ → 2Ag + O₂ + 2NO₂

The reaction is a decomposition reaction. Silver nitrate was decompose to it individual constituent.

AgNO₃ + KCI → AgCI + KNO₃

The balance equation is represented as follows:

AgNO₃ + KCI → AgCI + KNO₃

The reaction is a double displacement reaction. The  anions and cations of two different compound switch places, forming two entirely different compounds.

Ag + I₂ → AgI

The balance equation is as follows:

2Ag + I₂ → 2AgI

The reaction is a synthesis reaction. The individual elements combined to form a compound.

learn more on chemical equation here:https://brainly.com/question/23453237?referrer=searchResults

What is the molarity of the nitric acid solution if 20.5 mL of a 0.125 M lithium hydroxide solution are needed to titrate a 25.0 mL sample of the nitric acid solution

Answers

Answer:: We're asked to find the molar concentration of the NaCl solution given some titration data.

Explanation:

WILL BRAINLIST! NEED ANSWER!

• Why is it important to recycle metals?

A. to maintain sustainability
B. to create more tailings
C. to make sure ore remains renewable
D. to make it easier to extract ore from the ground

Answers

It’s C

Recycling metal is considered an environmentally friendly practice since it eliminates the demand for raw (ore) metal and conserves valuable natural resources

Explain why the first ionisation energy of beryllium is higher than the first ionisation
energy of lithium.

Answers

Answer:

since the distance between the electron and the nucleus is smaller in B than in Li, the electrostatic nuclear force of attraction experienced by B is higher than the one experienced by Li...this translates to the higher first ionization energy in B than in Li.

Explanation:

i hope it's helping!

Gold has a specific heat of 0.126 J/g.C. Copper has a specific heat of 0.386 J/g C. Which of the two metals would require more
heat energy to raise the temperature of the same weight of metal by 10.5C?

Answers

Answer:

The copper, because its specific heat is higher, meaning it takes more heat (Joules) per gram to raise the temperature 1 degree Celsius.

Explanation:

How many atoms are AI(OH)3 ?​

Answers

Answer:

It has a total of three elements and seven atoms. Another use that aluminum hydroxide has is it treats the symptoms of too much stomach acid. Some examples of what it treats are: upset stomach, heartburn, and acid indigestion.

Explanation:

Atomicity is the no of atoms present in one molecule. Atomicity of Al(OH)3 = 7.

Which condition is usually associated with low air pressure systems?

Answers

Answer:

clouds and precipitation that minimize temperature changes throughout the day

Explanation:

The side of a cube is found to be 127.58 mm and its mass is found to be 7.3 kg. Determine the density of this cube in g/mL.

Answers

Answer:

3.5154 g/mL

Explanation:

You will need to use the equation Density = Mass/Volume. You are given mm(can be used to find volume) of a cube and kg(mass). Since your answer is in g and mL we should convert it to those sizes. First we want cm so we will divide the 127.58 mm to cm getting 12.758 cm. We want to cube it since we are finding the whole area of a cube( 12.758*12.758*12.758) which will equal 2076.58 cm^3. We know that 1 mL is equal to 1 cm^3, so we can take our 2076.58 cm^3 and label them as mL(which is what we want). Then we know that there are 1000g in 1 kg, so if we multiply the 7.3 kg, we get 7300g. Finally use the equation Density = Mass/Volume to get your answer. 7300g/2076.58mL = 3.5154 g/mL.

Hope this helps!

1 point
Convert 3.79 x 10^24 atoms of sodium to grams.

Answers

Answer:

is easy to poiling

Explanation:

also is dificult to melting

Which model represents a compound with a 1:2 ratio?

Please explain your answer.

Answers

Answer:

D

Explanation:

D is the correct answer due to the fact that they way they are connected has 2 purple atoms and 1 orange one. thus would create a 1:2 ratio with 1 orange atom and 2 purple atoms.

A would create a 2:3 ratio, B wouldn't create a ratio comparable to the others, and C creates a 1:1 ratio with a few purple atoms floating around them, making all of the answers except D invalid.

In the given figures, the name of the model representing a compound with a 1:2 is figure D.

What is molar ratio?

Molar ration of any compound gives idea about the ratio of the concentration of given constituents present in that compound.

In the figure A molar ratio is 2:3, in figure B molar ratio of given constituents is not given because each molecule is composed of same types of atoms, in figure C molar ratio of given constitutes particles is 1:1 and in the figure D molar ratio of constituents is 1:2. Because in figure D, two atoms of one element and 1 atom of another element is present.

Hence, figure D is correct option.

To know more about molar ratio, visit the below link:
https://brainly.com/question/4408248

If there is a name/surname you can't make out due to a speaker's manner of speech, what are you supposed to do?

Answers

We can call a person by the word gentleman and Sir or from his/her real name.

If there is a name/surname you can't make out due to a speaker's manner of speech then I will call him gentleman or Sir or I will ask him his real name. Gentleman is a word that is used for noble person and Sir word is also used in order to give someone respect.

Call a person with his real name is also comes under the manner of speech so we can conclude that we can call a person by the word gentleman and Sir or from his/her real name.

Learn more about manner of speech here:

Learn more: https://brainly.com/question/26023566

the size of camphor kept in store house gradually decrease in size after few а days? ​

Answers

Answer:

Because it goes through the process of sublimation.

Explanation:

How do molecules work?

Answers

A molecule is essentially created by a collection of atoms linked by a network of bonds.

Other Questions
Which of the following would be the healthiest choice for breakfast? (5 points)A sweet cereal with a cup of low-fat milk and a fresh fruit cupScrambled eggs with bacon, buttered toast, and a fruit juice blendEqual portions of fresh fruit, low-fat yogurt, and multi-grain toastA cup of coffee with two tablespoons of cream and three of sugar The proportional relationship between the number of hours Taylor works, h, and her total earnings in dollars and cents, e, can be represented by the equation e=15.9he=15.9h. How much does she make in dollars and cents per hour? help me pls... .... Rearrange the following letters to spell the correct profession in Spanish. Do NOT include articles. Unscramble rotnip and Which word is a synonym of perpetual? Some bands get the opening slot on a major tour by paying the headliner for it. This is called a ______. 1. Which statement is true about naturalresources?A. They are only found in living things.B. They only provide sources of food andmaterial to humans.C. They can be man-made or found in nature.D. They can be a substance, material, object orsource of energy.2. How do the properties of a substance that isthe result of a chemical reaction compare to theproperties of the starting material?A. The properties will stay the same.B. The properties will be different.C. The properties stayed the same and newproperties will be added.3. Chlorine is a poisonous gas. Sodium reactsexplosively with water. When chlorine andsodium react with each other, the product isthe salt we sprinkle on our food. Whichprinciple does this demonstrate?A. Reactants are more dangerous than products.B. Energy is released by some reactions andabsorbed by others.C. When two reactants form one product, thereaction is spontaneous. Which graph represents the same relation as the rule y = 2x, for all real numbers x?A coordinate plane has 5 points. The points are (negative 2, negative 4), (negative 1, negative 2), (0, 0), (1, 2), (2, 4).On a coordinate plane, a horizontal line intercepts the y-axis at (0, 2).On a coordinate plane, a straight line with positive slope intercepts the axis at (0, 0). The line goes through points (negative 2, negative 4) and (2, 4).On a coordinate plane, 11 points form a vertical line that crosses the x-intercept at (2, 0). which option is the best example of slant rhyme How does the author of "Let Bindi Have the Limelight" persuade readers to consider the importance of wildlife conservation?She describes what a great stage performer Bindi is.She tells how difficult it was for Bindi to lose her father.She describes Bindi's message and accomplishments.She tells how Bindi and her mother worked together. The best strategy for an active listener to apply is tothink about the way the audience reacts to the speaker.pay close attention to what the speaker is saying.memorize as much of the argument as possible.mentally replay previous debates that were successful.B maybe? Valley Forge became famous because it was PLEASE HELPPPP. I really need it How many factor pairs does 15 have What does the article suggest about the use of punishment in learning under stressful situation? A) punishments are more easily remembered than rewarding consequences when under stress. B) rewarding behaviors, even under stress, is not as effective as punishments are. C) punishing behaviors is more effective than reinforcement when learning while under stress D) punishing behaviors is less effective and results in less accurate learning than reinforcement Marsha deposited $5,500 into a savings account 5 years ago. The simple interest rate is 3%. How much money did earn in interest? Substitute the values into the equation.Interest : $_ x _ x _% what is the correct term to use when referring to any surgery to assist a person with aligning their body to their felt gender? Please HelpIdentify the underlined place in 81.7277. Then round the number to that place.Underlined place is 2/Twohundredths; 81.72thousandths; 81.73thousandths; 81.72hundredths; 81.73 explanation of whats happening please help, due tonight help plzzzzz i need help