plz help it's urgent​

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.

Explanation:

1.42 Moles are there

Answer:

A. Empirical formula => SiCl₂I₂

B. Molecular formula = SiCl₂I₂

Explanation:

From the question given above, the following data were:

Silicone (Si) = 7.962 %

Chlorine (Cl) = 20.10 %

Iodine (I) = 71.94 %

Molar mass of compound = 352.8 g/mol

Empirical formula =?

Molecular formula =?

A. Determination of the empirical formula of the compound.

Si = 7.962 %

Cl = 20.10 %

I = 71.94 %

Divide by their molar mass

Si = 7.962 / 28 = 0.284

Cl = 20.10 / 35.5 = 0.566

I = 71.94 / 127 = 0.566

Divide by the smallest

Si = 0.284 / 0.284 = 1

Cl = 0.566 / 0.284 = 2

I = 0.566 / 0.284 = 2

Empirical formula => SiCl₂I₂

B. Determination of the molecular formula of the compound.

Empirical formula => SiCl₂I₂

Molar mass of compound = 352.8 g/mol

Molecular formula =?

Molecular formula = [SiCl₂I₂]ₙ

[SiCl₂I₂]ₙ = 352.8

[28 + (2×35.5) + (2×127)]n = 352.8

[28 + 71 + 254]n = 352.8

353n = 352.8

Divide both side by 353

n = 352.8 / 353

n = 1

Molecular formula = [SiCl₂I₂]ₙ

Molecular formula = [SiCl₂I₂]₁

Molecular formula = SiCl₂I₂

Answer:

67g/mol

Explanation:

The given compound is:

          NH₄NO₃ :

Problem here is to find the molar mass of the compound.

 Now;

The molar mass is the sum of the atomic masses of the elements in the compound.

   Atomic mass of N  = 14g

   Atomic mass of H  = 1g

   Atomic mass of O  = 16g

So;

   Molar mass = 14 + 4(1) + 1 + 3(16) = 67g/mol

Answer:

the answer is 80.0 grams per mole

Explanation:

Answer:

Molality (m), or molal concentration, is the amount of a substance dissolved in a certain mass of solvent. It is defined as the moles of a solute per kilograms of a solvent.

Explanation:

Look in Dictionary

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)

Answer:

do you have a picture of the choices?

Answer:

B: Single Displacement Reaction

Explanation:

A single replacement reaction, sometimes called a single displacement reaction, is a reaction in which one element is substituted for another element in a compound.

A + BX -> B + AX

For example:

Cation Replacement

Zn + CuCl2 -> ZnCl2 + Cu

Anion Replacement

Br2 + 2Ki -> 2KBr + I2

You just switch either the cation with another anion or switch an anion with another cation.

Hope it helped!

Answer:

Mass = 112 g

Explanation:

Given data:

Mass of CO₂ produced = 90.6 g

Mass of oxygen needed = ?

Solution:

Chemical equation:

C₃H₈ + 5O₂       →      3CO₂+ 4H₂O

Number of moles of CO₂:

Number of moles = 90.6 g/ 44 g/mol

Number of moles = 2.1 mol

Now we will compare the moles of  CO₂ and oxygen:

                 CO₂           :           O₂

                    3             :            5

                    2.1           :        5/3×2.1 = 3.5

Mass of oxygen needed:

Mass = number of moles × molar mass

Mass = 3.5 mol × 32 g/mol

Mass = 112 g

Answer:

1. True

2. resting position

3. 5 cm

4. Compressions

5. false

6. 7 m

7. true

8. second one has more amplitude

9. True

10. true

Explanation:

Answer:  the law that the product of the pressure and the volume of one gram molecule of an ideal gas is equal to the product of the absolute temperature of the gas and the universal gas constant.An ideal gas is a gas that conforms, in physical behaviour, to a particular, idealized relation between pressure, volume, and temperature called the ideal gas law

Answer:

0.82 mole of PCl₃

Explanation:

We'll begin by calculating the number of mole in 25.4 g of P₄. This can be obtained as follow:

Mass of P₄ = 25.4 g

Molar mass of P₄ = 4 × 31 = 124 g/mol

Mole of P₄ =?

Mole = mass / Molar mass

Mole of P₄ = 25.4 / 124

Mole of P₄ = 0.205 mole

Next, the balanced equation for the reaction. This is illustrated below:

P₄ + 6Cl₂ —> 4PCl₃

From the balanced equation above,

1 mole of P₄ reacted to produce 4 moles of PCl₃

Finally, we shall determine the number of mole of phosphorus trichloride, PCl₃, produced by the reaction of 25.4 g (i.e 0.205 mole) of P₄. This can be obtained as follow:

From the balanced equation above,

1 mole of P₄ reacted to produce 4 moles of PCl₃.

Therefore, 0.205 mole of P₄ will react to produce = 0.205 × 4 = 0.82 mole of PCl₃

Thus, 0.82 mole of PCl₃ was obtained from the reaction.

Answer:

b) different branches of science are connected

Answer:

b

Explanation:

a p e x :)

The average atomic mass unit of Silicon : 28.0774

Given

Isotopes of Si(Silicon-28, Silicon-29, Silicon-30)

Required

The average atomic mass

Solution

Isotopes are elements that have the same Atomic Number (Proton)

Atomic mass is the average atomic mass of all its isotopes

Avg. atomic mass = %mass.isotopes 1 + %mass.isotopes 2...etc

Input the values :

Avg atomic mass = (0.922 x 27.977) + (0.047 x 28.976) + (0.031 x 29.974)

Avg atomic mass = 28.0774

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

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)

Answer:

The answer is "how closely the model's behavior matches the real world "

Explanation:

Your options were glitched out, so it only showed A and C, and B and D were blank so lol

Answer:

Pressure is often defined as a measure of force applied on an area, or over a unit area.

Explanation:

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

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:

https://brainly.com/question/11934397

#SPJ2

Answer:

See detailed explanation.

Explanation:

Hello!

In this case, for the described chemical reaction, we can proceed as follows:

A) For the complete chemical reaction we note down every reacted and produced species as well as the proper balancing process:

[tex]2NaBr(aq)+Cl_2(aq)\rightarrow 2NaCl(aq)+Br_2(g)[/tex]

In which gaseous bromine may give off.

B) The dissociated ionic equation requires the ionization of the aqueous species in ions, expect for chlorine which is not ionized:

[tex]2Na^+(aq)+2Br^-(aq)+Cl_2(aq)\rightarrow 2Na^+(aq)+2Cl^-(aq)+Br_2(g)[/tex]

C) For the net ionic equation we cancel out the sodium ions as they are at both reactants and products:

[tex]2Br^-(aq)+Cl_2(aq)\rightarrow +2Cl^-(aq)+Br_2(g)[/tex]

D) Based on C) we infer that the spectator ions here are the sodium ions.

Best regards!

Answer:

true mass is based on gravity

Answer:

true

Explanation:

mass based on gravity

Answer:

Compound 1- ionic solid

Compound 2- can't really decide

Compound 3- molecular solid

Explanation:

An ionic solid has a very high melting point. It is hard but not brittle. It's solution or melt but not it's solid conducts electricity. Compound 1 is an ionic solid.

We can't really decide on compound 2 since it is brittle yet it's solution conducts electricity.

Lastly, compound 3 is a molecular solid since it has a low melting point.

Answer:

Compound 1- ionic solid

Compound 2- can't really decide

Compound 3- molecular solid

Explanation:

Answer:

i think iron

Explanation:

i not sure with my ans

Answer:

D.Mixture

Explanation:

When Salt dissolves in water a homogeneous mixture is formed, because the different components are mixed evenly within the substance.

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.

Answer:

*helps and doesnt get deleted*

Explanation:

Answer:

Comvection

Explanation:

The movement causes the density to rise and therefore transfer more heat