which of the following is an indicator of a chemical reaction?

A. two different compounds mixing and remaining seperate.

B. changing states of matter (solid to liquid).

C. decreasing in size.

D. increasing in tempurature​

Answers

Answer 1

Answer:

option . D

Increase in temperature

is an indicator of a chemical reaction

hope it helps

Answer 2

Answer:

answer is D

Explanation:

some signs of a chemical change are a change in colour and the formation of bubbles.

the five conditions of chemical change: colour change, formation of precipitate, formation of a gas ,odor change, temperature change.

I think it will use for you


Related Questions

PLeaseee ITS Timedddd + BrainlIESTT
A 6.50 gram piece of aluminum reacts with an excess of oxygen. use the balanced equation below to determine how many grams of aluminum oxide is formed during this reaction.
4 Al + 3 O2 --> 2 Al2O3
a. 662.7 grams of Al2O3
b. 6.1 grams of Al2O3
c. 24.6 grams of Al2O3
d. 12..3 grams of Al2O3

Answers

Answer:

d. 12.3 grams of Al2O3

Explanation:

Based on the reaction:

4Al + 3O2 → 2Al2O3

Where 4 moles of Al reacts in excess of oxygen to produce 2 moles of aluminium oxide.

To solve this question we must find the moles of Aluminium. With these moles we can find the moles of aluminium oxide using the reaction:

Moles Al -Molar mass: 26.9815g/mol-

6.50g * (1mol / 26.9815g) = 0.241 moles Al

Mass Al₂O₃ -Molar mass: 101.96g/mol-

0.241 moles Al * (2 mol Al2O3 / 4 mol Al) = 0.120 moles Al2O3

0.120 moles Al2O3 * (101.96g / mol) =

12.3g of Al2O3 are produced.

Right answer is:

d. 12.3 grams of Al2O3

Which statement describes particles of an ideal gas, based on the kinetic molecular theory?
A) Gas particles are separated by distances smaller than the size of the gas particles.
B) Gas particles do not transfer energy to each other when they collide.
C) Gas particles have no attractive forces between them.
D) Gas particles move in predictable, circular motion.

Answers

Answer:

The answer is C. Gas particles have no attractive forces between them.

Explanation:

Answer:

I also think the answer is C

A solution of HCl has a concentration of 3.4 x 10-3 M. What would be the [OH-] of this solution?

Answers

Answer:

a

Explanation:

uffvyffvfvf


Which term describes the following group of planets: Jupiter, Saturn, Uranus, and
Neptune?

Answers

Answer:

Gas giants.

Explanation:

Jupiter, Saturn, Uranus, and Neptune are the gas giants of our solar system.

List the following elements from increasing electronegativity: boron, magnesium, calcium, chlorine, argon

Answers

Answer:

The list of elements from increasing electronegativity: Calcium <  magnesium < chlorine < argon < boron.

Explanation:

In the periodic table if you move from left to right there would be an increase in the electronegativity of the elements. If you move from the bottom to the top of the groups in the periodic table the electronegativity increases and if u move to the bottom from down its decreases.

Calcium is in the 2nd group below magnesium so calcium is the least electronegative among given elements then magnesium and then chlorine as it is top of magnesium then argon, as it is right to the chlorine, and boron has the most electronegativity as it is above rest of the elements.

What is the [OH-] in a solution that has a pH = 9.23? *
O 1.7x10^5
O 8.2x10^-9
1.7x10^--5 M.

Answers

Answer:    1.7x10^-5

Explanation:

pH + pOH = 14

14 - pH = pOH

14 - 9.23 = 4.77

pOH =4.77

[OH-] = 10^-pOH

         = 10^-4.77

         = 1.698243x10^-5

         = 1.7x10^-5

What type of reaction is this?

Answers

Answer:

Decomposition

Number 2 is the correct answer

Which of the following solution(s) would be a buffer? Select all that apply.
a. 100.0 mL of a solution that contains 0.100 M benzoic acid and 0.100 M potassium benzoate
b. 100.0 mL of a 0.100 M propanoic acid to which 50.0 mL of 0.100 M sodium hydroxide has been added
c. 100.0 mL of a 0.100 M formic acid solution
d. 100.0 mL of a solution that contains 0.100 M hydrochloric acid and 0.100 M sodium chloride
e. 100.0 mL of a 0.100 M solution of acetic acid in which 0.100 g of sodium acetate is dissolved

Answers

Which of the following solution(s) would be a buffer? Select all that apply.
a. 100.0 mL of a solution that contains 0.100 M benzoic acid and 0.100 M potassium benzoate
b. 100.0 mL of a 0.100 M propanoic acid to which 50.0 mL of 0.100 M sodium hydroxide has been added
c. 100.0 mL of a 0.100 M formic acid solution
d. 100.0 mL of a solution that contains 0.100 M hydrochloric acid and 0.100 M sodium chloride
e. 100.0 mL of a 0.100 M solution of acetic acid in which 0.100 g of sodium acetate is dissolved

As a buffer is defined as the aqueous mixture of a weak acid and its conjugate base. Or a weak base and its conjugate acid. Thus:

a, b and e would be a buffer.

The benzoic acid is a weak acid, its conjugate base is the benzoate ion that comes from potassium benzoate. Thus: a is a buffer.

Propanoic acid (weak acid) reacts with a strong base as sodium hydroxide producing its conjugate base (propanoate ion). Thus, b is a buffer.

Formic acid is a weak acid but its conjugate base, formate ion is not present in the solution. Thus, c is not a buffer.

Hydrochloric acid is a strong acid and sodium chloride a salt. Thus, d is not a buffer.

Acetic acid is a weak acid, and its conjugate base, acetate ion (That comes from sodium acetate) is present in the solution. Thus, e is a buffer.

Balance the following reaction
HgO → _ Hg +_ 02

Answers

Answer:

reeeeeeeeeeeeeeeeeeeee

Explanation:

cancer

2HgO -> 2Hg + O2. Hope it helps.

GAS LAW:
If 2.2 liter of hydrogen are heated from 0 degrees celsius to 95 degrees celsius at the constant pressure what is the new volume?​

Answers

Answer:

bh yftd5xsdcfvgbhnjm

Explanation:

Students place paper clips on a desk and then hold a magnet under the desk. What evidence would BEST show that the
magnetic field was able to pass through the desk?
O A The top of the desk is made of a kind of plastic.
OB. The paper clips move when the magnet is moved under the desk.
OC. The magnet they are using is the largest one in the classroom.
OD. The students were able to pick up these paper clips with a magnet.


Answers

Answer:

B

Explanation:

got it right on test

Answer:

Yes the correct answer is B

Explanation:

Have a good day!!!

HF + NaOH ---> NaF + H2O
If you need 1785 g of NaF (sodium Fluoride) how many grams of HF (hydrofluoric acid) do you need?

Answers

Answer:

so calculate moles of 1785 g of NaF

this is something = 1785/41.98 =42.52 moles

now one moles of HF is forming one mole of NaF so to get 42.52 moles of NaF we need 42.52 moles of HF

mass = moles × molar mass

mass of HF = 42.52×20.01

mass of HF = 850.82 g

so the conclusion is if you need 1785 g of NaF (sodium Fluoride) you need 850.82 grams of HF (hydrofluoric acid) !!!

I d k it's right or wrong but i tried to solve it, please let me know is it correct or not!!

1. Scientists measured the spot size of guppies (small fish) in two different populations. Which
population has more guppies with large spots?
a
They both have the same number of guppies with large spots.
b
The population in Brazil has more guppies with large spots.
С
The population in Venezuela has more guppies with large spots.
d
These bar graphs do not show which population has more guppies with large spots.

Answers

Answer: the answer is C

Explanation:

Can someone help me out with why is the outer core of Earth is important in you’re own words?! A mini paragraph plsss

Answers

Answer:

the outer core is important because the outer core is responsible for earth's magnetic field which protects earth from harmful particles that comes from sun and also contains some natural metal like nikle and iron.

is this much paragraph enough comment down below..

hope this helps you ☺️☺️

A 2.25 mol sample of oxygen occupies 1.80 L at 25.0°C. What volume will
it occupy with 3.7 moles?

Answers

Answer:

2.96 L

Explanation:

We apply the Ideal Gases Law to determine this:

P . V = n . R . T

Firstly we need to know the pressure for the 2.25 moles

P . 1.80L = 2.25 mol . 0.082 L.atm/mol.K . 298K

(We convert T°C to T°K, 25°C + 273 = 298K)

P = (2.25 mol . 0.082 L.atm/mol.K . 298K) / 1.80L

P = 30.5 atm

So now, we apply the pressure value for the new conditions:

30.5 atm . V = 3.7 mol . 0.082 . 298K

V = (3.7 mol . 0.082 . 298K) / 30.5atm = 2.96 L

Calculate the molarity of a solution of 0.030 mol of HCl in 0.15L of solution?

Answers

Answer:

0.20M

Explanation:

Molarity (by definition) = moles / Volume in Liters

∴Molarity = 0.030mol/0.15Liter = 0.20M

help please
If you have 100 grams of a radioactive isotope with a half-life of 10 years:
part a: How much of the isotope will you have left after 10 years?
part b: How much of the isotope will you have left after 20 years?
part c: How many half-lives will occur in 40 years?

Answers

Answer:

part a: How much of the isotope will you have left after 10 years?

100/2 = 50 g

part b: How much of the isotope will you have left after 20 years?

50/2 = 25 g

part c: How many half-lives will occur in 40 years?

40/10 = 4

K,Co, is added to a volume of distilled water. Which of the following statements is correct? (1) The freezing and boiling points increase. (2) The freezing and boiling points decrease. (3) The freezing point increases and the boiling point decreases. (4) The freezing point decreases and the boiling point increases​

Answers

The answer for this question is is 2!! Sorry if I’m wrong :( good luckk!!! :)))

A student measures out 5 mL of calcium chloride solution into a small container and 5 mL of sodium carbonate solution in another small container. The total mass of both chemicals and the containers they are in is 15.5 g. When the student combined the two clear liquids, a gooey, cloudy precipitate formed. What would the total mass of the products and the two containers be after this reaction took place?

Answers

Answer:

15.5g

Explanation:

"The total mass of both chemicals and the containers they are in is 15.5 g." After a chemical reaction, by conservation of mass, the total mass of the products and the two containers after reaction is the same at 15.5g.

Answer:

15.5

Explanation:

in a chemical reaction, mass is conserved

so mass after reaction = mass before reaction = 15.5 g

Look at each Lewis Dot Diagram for the following elements. How many electrons are needed to fill the outer shell?

Answers

1. 4 more electrons
2. 1 more electron
3. 3 more electrons

The goal is to have 8 electrons in the outer shell of each atom.

The number of electrons are needed to fill the outer shell of the given figures are 4,1 & 3 respectively.

What is Lewis dot structure?

Lewis dot structure shows the boding within the molecule by showing the number of electrons and lone pairs present in each atoms present in that molecule.

As we know that bonding in any molecule takes place to complete the octet configuration of outer most shell and get stability.

In the figure (1), 4 electrons are shown in the outer shell then we need 4 electrons to complete the octet.In the figure (2), 7 electrons are shown in the outer shell then we need 1 electron to complete the outer most shell to complete the octet.In the figure (3), 5 electrons are shown in the outer shell then we need 3 electrons to complete the outer most shell to complete the octet configuration.

Hence required no. of electrons are 4,1 & 3 respectively.

To know more about Lewis dot structure, visit the below link:

https://brainly.com/question/6605265

"Reduce, reuse, recycle." Give examples of how one or more of

these ideas can be applied to the issues and practices of hydraulic

fracturing for the acquisition of shale gas.

Answers

Answer:

Examples of how the ideas can be applied to the issues and practices of hydraulic fracturing for the acquisition of shale gas are;

Reuse; The produced water in obtained from oil and gas well production are reused for fracking, drilling, and if the water is good enough, it can be used for farming

Reduce; The use of recycled brine and water in drilling and fracking process reduces the application of freshwater in the those processes and reduces pollution of natural water sources

Recycle; Recycling involves creating products from waste. In the hydraulic fracturing process approximately 13 percent of the water produced and the flowback water are recycled to be used more than once thereby reducing the net consumption of freshwater

Explanation:

In hydraulic fracturing, also known informally as fracking, is the drilling method used in oil and gas well development process that makes use of water sand and chemical injection through the well bore to open and widen cracks in the bedrock formations in the areas around the wellbore.

When a strong acid is placed into water, what percentage of hydrogen ions (H+) will dissociate into the solution?

Answers

It will be dissociate

How do differences in
electronegativity and molecular shape
make some molecules more able to
absorb heat?

Answers

Answer:

So, higher electronegativity helps atoms take more control over shared electrons creating partial negative regions and partial positive regions which result in dipoles that cause polarity. The molecule's polarity will be determined on the negative and positive regions on the outer atoms in the molecule

If anyone is taking Integrated Physics and Chemistry (2014) on sos can u pls help me w something !! Thanks

Answers

I am so sorry i cant help but good luck

Which of the following equations is balanced?
2H2 + O2 + 4H20
4Na + O2 - 2Na20
Fe2O3 + H2 - 2Fe + 3H20
CH4 + O2 - CO2 + H20

Answers

Answer:

4Na + O2 - 2Na20

Is the balanced equations .

as- The salt left in the evaporating
basin is often a little dirty
suggest what you could do to
get cleaner salt

Answers

Answer:

Pour the filtrate into an evaporating basin. Heat the salt solution gently until it starts to decrepitate .keep eye protection on and do not get too close. Turn off the Bunsen burner and let the damp salt dry in the dish

In evaporation particles of water take energy in the form of sunlight from the surrounding and then convert into vapor phase. Therefore heating is the only technique for getting pure salt.

What is evaporation?

Evaporation is a physical process in which the water in liquid state converts to gaseous state at the temperature below its boiling point. Evaporation happens before the boiling process.

Evaporation causes cooling effect in the surrounding. During summer when water is kept in earthen pot water cools, this is because of the evaporation process.

Evaporation is affected by temperature. As the temperature increases the rate of evaporation increases and hence in summer there is more evaporation and hence there is lot more water in air.

Pour the filtrate into an evaporating basin. Heat the salt solution gently until it starts to decrepitate .Turn off the Bunsen burner and let the damp salt dry in the dish.

Therefore heating is the only technique for getting pure salt.

To know more about evaporation, here:

https://brainly.com/question/8169606

#SPJ2

What is the pH of a solution that is 100x more acidic than a solution with a pH of 5?

Answers

Answer:3

Explanation:

How many chloride ions are in a 220 grams of calcium chloride?
A)
1.3 x 1026 ions
B)
1.5 x 1028 ions
2.4 x 1024 ions
D)
3.0 x 1023
La

Answers

Answer: Hello, There! Your Answer is Below

2.4 x 1024 ions

Explanation:

220 g of CaCl₂  =  X moles

Solving for X,

                                                X  =  (220 g × 1 mol) ÷ 110.98 g

                                                X  =  1.98 moles

As,

                          1 mole contained  =  1.20 × 10²⁴ Cl⁻ Ions

Then,

                   1.98 mole will contain  =  X Cl⁻ Ions

Solving for X,

                                                 X  =  (1.98 mol × 1.20 × 10²⁴ Ions) ÷ 1mol

                                                 X  =  2.38 × 10²⁴ Cl⁻ Ions

Hope this Helps!

Have a great DAy!

`August~

2.4 × 1024 chloride ions are in 220 grams of calcium chloride. The correct option is c.

What is the calculation and what are chloride ions?

Calculation

220 g of CaCl2 = X moles

Solving for X,

X = (220 g x 1 mol) 110.98 g

X = 1.98 moles

As

1 mole contains = 1.20 x 1024 chloride Ions

Then,

$1.98 mole will contain = X Chloride Ions

Solving for X,

X = (1.98 mol x 1.20 x 1024 lons) ÷ 1mol

X =  2.38 x 10²⁴ Chloride Ions

Chloride Ion is a chlorine anion that fo²²rms the negatively charged part of certain salts, including sodium and hydrogen chloride salts, and is an essential electrolyte located in all body fluids responsible for maintaining acid/base balance, transmitting nerve impulses and regulating fluid in and out of cells.

Chloride is a halide anion formed when chlorine picks up an electron to form an anion.

Learn more about chloride, here:

https://brainly.com/question/15296925

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6. Too much rainwater can cause a slope or hillside to collapse through a process called a
(6 Points)
mudslide
snowslide
o avalanche
storm

Answers

Answer:

mudslide

Explanation:

a mass of mud and other earthy material that is falling or has fallen down a hillside or other slope

The answer is Mudslide brother, I hope this helps

For a constant waves speed,wavelength,of the wave increases with a(n)______

Answers

Answer:

higher frequency

Explanation:

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