Which is a definite sign of a chemical reaction?

Chemical properties change.

Physical properties change.

A gas forms.

A solid forms

Answers

Answer 1

Answer: here i am choosing two answer because i am not sure . a gas forms and a solid forms

Explanation: a solid forms thus is to say a precipitate is formed

a gas forms thus to say effervescence , fizzing and bubbling whiles a gas is being produced.


Related Questions

How does increased exhalation of CO2 at the lungs (pulmonary regulation) restore the correct pH range?

Answers

Answer:

When CO2 levels become excessive, a condition known as acidosis occurs. This is defined as the pH of the

blood becoming less than 7.35. The body maintains the balance mainly by using bicarbonate ions in the

blood. As the body responds to neutralize this condition, an electrolyte imbalance – an increase of plasma

chloride, potassium, calcium and sodium, can occur.

What volume would be occupied by 16.0 g of CH4 at 00C and 760 mmHg?

Answers

Answer:

22.4 L

Explanation:

We'll begin by calculating the number of mole in 16.0 g of CH₄. This can be obtained as follow:

Molar mass of CH₄ = 12 + (4×1)

= 12 + 4

= 16 g/mol

Mass of CH₄ = 16 g

Mole of CH₄ =?

Mole = mass / molar mass

Mole of CH₄ = 16 / 16

Mole of CH₄ = 1 mole

Finally, we shall determine the volume of the gas. This can be obtained as follow:

Number of mole of CH₄ (n) = 1 mole

Pressure (P) = 760 mmHg = 1 atm

Temperature (T) = 0°C = 273 K

Gas constant (R) = 0.0821 atm.L/Kmol

Volume (V)?

PV = nRT

1 × V = 1 × 0.0821 × 273

V = 22.4 L

Therefore, the volume of the gas is 22.4 L

Calculate the density of the baseball. Use the formula
D= m/V
where D is the density, m is the mass, and V is the
volume.
Determine whether the density of baseball is within the
legitimate range for an official baseball.
Record your answers in Table C of your Student Guide.
What is the density of the baseball?
g/cm3
The acceptable density range of official baseballs is
between 0.70 g/cm3 and 0.80 g/cm3. Is the
questionable ball in this range of acceptable density?

Answers

Answer:

0.73 and yes

Explanation:

The answers are 0.73 and yes! <3 ^-^

Hydrogen gas reacts with oxygen gas to form water. At STP, how many liters of hydrogen gas react with 32.4 liter of oxygen gas? (H2 + O2 -> H2O)

Answers

Answer:

I think its 1.2L? i may be wrong

Explanation:

Recall old Avogadro's hypothesis...........

Equal volumes of gases contain AN EQUAL NUMBER of PARTICLES

And thus if there are

2.4

L

of dihydrogen, stoichiometric equivalence requires

1.2

L

of dioxygen. How many litres of water g

What is the pH of a 0.21 M solution of LiOH?

Answers

Answer:

13.32

Explanation:

pOH=-log(0.21)=0.68

pH=14-pOH=14-0.68=13.32

an organism that lives in or on another organism and causes harm to is a
A. host
B. parasite
C. prey
D. producer

Answers

the answer is B. Parasite.

Which is a physical change? A) Rusting iron B) Burning paper C) Reacting baking soda and vinegar D) Separating a mixture of salt and wat

Answers

Answer:

D

Explanation:

how many moles of gold is 9.75 x 10^24 atoms?

Answers

Answer:

1 Answer. You use the fact that 1 mole of any substance contains exactly 6.022⋅1023 atoms or molecules of that substance - this is known as Avogadro's number. In your case, 1 mole of gold will have exactly 6.022⋅1023 atoms of gold.

Explanation:

Answer:

[tex]\boxed {\boxed {\sf 1.62 \ mol \ Au}}[/tex]

Explanation:

We are asked to convert atoms to moles.

1. Avogadro's Number

We know that 1 mole of any substance contains the same number of particles (atoms, molecules, formula units etc.) This is Avogadro's Number: 6.022*10²³. For this question, the particles are atoms of gold (Au).

2. Convert Atoms to Moles

Let's set up a proportion using this information.

[tex]\frac {6.022*10^{23} \ atoms \ Au}{1 \ mol \ Au}[/tex]

Since we are solving for the moles in 9.75 * 10²⁴ atoms, we multiply by that number.

[tex]9.75*10^{24} \ atoms \ Au*\frac {6.022*10^{23} \ atoms \ Au}{1 \ mol \ Au}[/tex]

Flip the proportion. It will be equivalent, but the units of "atoms Au" can cancel.

[tex]9.75*10^{24} \ atoms \ Au*\frac {1 \ mol \ Au}{6.022*10^{23} \ atoms \ Au}[/tex]

[tex]9.75*10^{24} *\frac {1 \ mol \ Au}{6.022*10^{23}}[/tex]

Condense the problem into 1 fraction.

[tex]\frac {9.75*10^{24} }{6.022*10^{23}}\ mol \ Au[/tex]

[tex]1.619063434 \ mol \ Au[/tex]

3. Round

The original measurement (9.75) has 3 significant figures. Our answer must have the same. For the number we found, that is the hundredth place.

1.619063434

The 9 in the thousandth place tells us to round the 1 to a 2 in the hundredth place.

[tex]1.62 \ mol \ Au[/tex]

9.75 * 10²⁴ atoms of gold is approximately equal to 1.62 moles of gold.

ANSWER THESE 3 QUESTION AND I WILL GIVE OUT THE BRAINLIEST
1. what is a positive acceleration
2. what is a zero acceleration
3. what is a negative acceleration

Answers

Answer:

A positive acceleration means and increase

A negative acceleration is a decrease

a zero acceleration is a constant movement so its not increasing or decreasing just constant

Explanation:

[tex] \sf \pink{Question}[/tex]

What is a positive acceleration ?

[tex] \sf \blue{Answer}[/tex]

If the velocity of an object increases with time, its acceleration is positive.

[tex] \sf \pink{Question}[/tex]

What is a zero acceleration ?

[tex] \sf \blue{Answer}[/tex]

Zero acceleration is an acceleration, just with zero magnitude. Motion with constant velocity is just a special case of motion with uniform acceleration.

[tex] \sf \pink{Question}[/tex]

What is a negative acceleration ?

[tex] \sf \blue{Answer}[/tex]

A negative acceleration means you will subtract from the current value of the velocity, and a positive acceleration means you will add to the current value of the velocity. ... And if the acceleration points in the opposite direction of the velocity, the object will be slowing down.

Which shows an isomer of the molecule below?

Answers

Answer: C

Explanation:

Don’t trust the other person it’s not A

*view photo for answer*

pay attention! the answer choices aren't always in the same order!

Which combinations of particles form ionic bonds/compounds?

Answers

Answer:

Iconic bond is formed by cation and anion. A compound is made when atoms of two or more elements bond in a chemical reaction.

Explanation:

The speed you read from your speedometer is your ____________________. *
average speed
direction
instantaneous speed
distance

Answers

Instantaneous speed because that is the speed in which the object (the car) is at in a given moment.

Answer:

it is your instantaneous speed

Explanation:

What is the molar mass of H2S?
0 518
65.15 g
17 g
78.16 g
34.1g

Answers

H - 1
S - 32.1

(1*2) + 32 = 2 + 32.1 = 34.1

34.1 g is the answer

what is the mass of 4 moles of almunium atom​

Answers

Answer:

108 grams

Explanation:

BrainlieSTTTTTT A gas is originally stored at a pressure of 25 atm with a volume of 3 L. If the pressure were increased to 75 atm, what would be the new volume of the gas?
a.8.333 L
b.1 L
c.75 L
d.1 L

Answers

Explanation:

Apply Boyle's Law :-

P1V1 = P2V2

Where P1 is 25 atmV1 is 3LP2 is 75 atmV2 is what we need to find out.

25 × 3 = 75 × V2

[tex]\tt{V_2 = \dfrac{ 25 \times 3}{75}}[/tex]

[tex]\tt{V_2 = \dfrac{75}{75}}[/tex]

So, the answer is d) Part, 1L .

Hope it helps :)


How do textbooks usually describe Le Châtelier's famous principle

Answers

Answer:is an observation about chemical equilibria of reactions. It states that changes in the temperature, pressure, volume, or concentration of a system will result in predictable and opposing changes in the system

Explanation:

The chemical name for MgCl3

Answers

Answer:

The chemical name is magnesium chloride

Answer:

Magnesium chloride

Please mark as brainliest if answer is right

Have a great day, be safe and healthy  

Thank u  

XD

if 300.0g of chlorine is reacted how much calcium hydroxide is needed to react with it

Answers

Answer:

334.7g of Calcium Hydroxide are needed

Explanation:

Based on the reaction:

2Ca(OH)2 + 2Cl2 → Ca(ClO)2 + CaCl2 + 2H2O

2 moles of chlorine react with 2 moles of calcium hydroxide.

To solve this question we must find the moles of chlorine in 300.0g. These moles = Moles of Ca(OH)2. With the moles of calcium hydroxide we can find its mass as follows:

Moles Cl₂ (Molar mass: 70.90g/mol)

300.0g Cl₂ * (1mol / 70.90g) = 4.2313 moles Cl₂ = Moles Ca(OH)₂

Mass Ca(OH)₂ (Molar mass: 74.093g/mol)

4.2313 moles Ca(OH)₂ * (74.093g / mol) =

334.7g of Calcium Hydroxide are needed

Write in the correct coefficients for the balanced equation:

Na +
Cl2 →
NaCl

Answers

Answer:

Na+Cl2-----NaCl

Explanation:

it's the chemical formula of common salt.

Answer:

2Na + Cl2 → 2NaCl

Explanation:

Na + Cl2 → NaCl

We have two chlorines on the left but only one on the right so it needs to be balanced.

If we put a 2 in front of NaCl we now have 2 chlorines on both sides but now 2 sodiums on the left and one on the right

Add another 2 in front of Na to get the full balanced equation

2Na + Cl2 → 2NaCl

How is ethanol DIFFERENT from gasoline?

A. Ethanol is alcohol; gasoline is fuel.
B. Ethanol becomes a bacteria; gasoline becomes a chemical.
C. Ethanol helps break down yeast; gasoline is a by-product of
yeast.
D. Ethanol is made from oranges; gasoline is made from
petroleum

Answers

The correct answer is A. Ethanol is alcohol; gasoline is fuel.

Consider the reaction.

2HF(g) +

H2(g) + F2(g)

At equilibrium at 600 K, the concentrations are as follows.

[HF] = 5.82 x 10-2 M

[H2] = 8.4 x 10-3M

[F2] = 8.4 x 10-3M

What is the value of Kea for the reaction expressed in scientific notation?

O 2.1 x 10-2

102.1 x 102

1.2 x 103

0 1.2 x 10-3

Answers

Answer:

0.021

Explanation:

Step 1: Write the balanced equation

2 HF(g) ⇄ H₂(g) + F₂(g)

Step 2: Calculate the value of the concentration equilibrium constant

The concentration equilibrium constant (K) is equal to the product of the concentrations of the products raised to their stoichiometric coefficients divided by the product of the concentrations of the reactants raised to their stoichiometric coefficients.

K for this reaction is:

K = [H₂] × [F₂] / [HF]²

K = (8.4 × 10⁻³) × (8.4 × 10⁻³) / (5.82 × 10⁻²)² = 0.021

What is the momentum of a motorcycle and a rider weighing 215 kg traveling at a speed of 62 meters per second?

Answers

Answer:

[tex]p=13330kg*\frac{m}{2}[/tex]

Explanation:

Hello there!

In this case, since the momentum of any body is calculated by multiplying the mass and the velocity:

[tex]p=m*v[/tex]

We simply need to multiply the 215 kg of the motorcycle by the velocity it has, 62 m/s to obtain:

[tex]p=215kg*62m/s\\\\p=13330kg*\frac{m}{2}[/tex]

Regards!

How many moles of NaOH are in a 50.0 g sample of NaOH?

Answers

Answer:

The answer should be, 0.01

Explanation:

0.01 = moles of NaOH

[tex] \huge\boxed{ \boxed{\boxed{ \boxed{\mathcal{Answer ࿐ }}}}}[/tex]

[tex] \mathrm{1 \: mole \: of \: NaOH = 40 \: g }[/tex]

[tex] \mathrm{1g = \dfrac{1}{40} \: moles \: of \: NaOH}[/tex]

[tex] \mathrm{50g = \dfrac{1}{40} \times 50}[/tex]

[tex] \mathrm{1.25 \: moles \: of \: \: NaOH}[/tex]

_____________________________

[tex]\mathrm{ \#TeeNForeveR}[/tex]

Which of these would most likely happen to a species that is not able to adapt to a changing environment?

Answers

Answer:

If a species cannot adapt to the changes in their ecosystem, they may move to another location. If they will not move, the species may become threatened, endangered or extinct.

Explanation:

The way the question is worded, it sounds like there are options for you to chose from that you are not showing. I could help you out more if I actually knew the options.

Extinction is likely if conditions change faster than a species can evolve, and if members of that species lack the traits required to survive in the new environment.

What is an extinction ?

The death of all members of a species of plants, animals, or other organisms is referred to as extinction.

The primary cause of higher extinction rates is habitat loss. Other causes include habitat changes, commercial overexploitation of wildlife, the introduction of harmful nonnative species, pollution, and disease spread.

If a species is unable to adapt to changes in its ecosystem, it may relocate. The species may become threatened, endangered, or extinct if they do not move.

Thus, Extinction is likely if environmental conditions change faster than a species can evolve and members of that species lack the traits needed to survive in the new environment.

To learn more about the extinction, follow the link;

https://brainly.com/question/14480057

#SPJ6

At which positions will the Earth have spring and fall?

Answers

Answer:

In fall and spring the planets axis is in line with the sun. It's directly over the equator, equally hitting the northern and southern hemispheres.

A car travels at 24km/hr to the north. Then it travels 24km/hr to the east. Which is true about the car's acceleration?

a
The car accelerated because it speed increased.
b
The car accelerated because it changed direction.
c
The car did not accelerate because its speed did not change.
d
Only the velocity changed, not the acceleration not the acceleration.

Answers

Answer:

D

Explanation:

Define trace gas in simple ​

Answers

Trace gases are those gases in the atmosphere other than nitrogen (78.1%), oxygen (20.9%), and argon (0.934%) which, in combination, make up 99.934% of the gases in the atmosphere (not including water vapor).

50 POINTS!!!

When writing a chemical reaction equation, what does the arrow ( ---> ) represent?

A. the reactants are making the products
B. the direction of the chemical equation
C. the chemical reaction cannot be reversed
D. all of the above

Answers

The condition or progress of a reaction is represented by reaction arrows. The chemical reaction arrow is a single straight arrow that points from the reactant(s) to the product(s) and by-products, as well as side products.

I think this should help you find the answer more easy!

Describe the process used to dilute a stock solution?

Answers

Answer:

Heyaa!! I'm *✧・゚:*Pinky!! *:・✧ And i'm here to inform you that you're answer is...

Explanation:

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Al hacer reaccionar 5g de cinc con ácido sulfúrico se observa que la reacción ocurre en 20s. ¿Cuál será la rapidez de la reacción? Masa atómica del cinc 65,37g.

Answers

Answer:

0.0038 mole s-1

Explanation:

La velocidad de una reacción se refiere a la rapidez o la lentitud con que avanza una reacción. Se mide por la cantidad de reactivos que desaparecen por unidad de tiempo o por la cantidad de productos que aparecen por unidad de tiempo.

Número de moles de zinc = 5g / 65.37gmol-1 = 0.076 moles

Velocidad de reacción = 0.076 moles - 0 moles / 20 s - 0s = 0.0038 mole s-1

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