PLZ HELP IT BEING TIMED!!!!!! PLZ ANSWER!!!!!

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.

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:

*helps and doesnt get deleted*

Explanation:

Answer:

b) different branches of science are connected

Answer:

b

Explanation:

a p e x :)

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:

D.Mixture

Explanation:

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

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:

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:

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

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:

D

Explanation:

Just took the test, Hope this helps!

Answer:

B. Atomic radius decreases along periods and increases down groups.

Explanation:

It decreases in period because of addition of proton effective nuclear charge increase and atomic radius decreases.

Atomic radius increases in group because of addition of shells

Explanation:

1.42 Moles are there

Answer:

0.768g of Fe are in the tablet = 38.4% by mass of Fe in the tablet

Explanation:

The balanced redox equation of Fe²⁺ with KMnO₄ in acidic medium is:

5Fe²⁺ + MnO₄⁻ + 8H⁺ → 5Fe³⁺ + Mn²⁺ + 4H₂O

Where 5 moles of Fe²⁺ react per mole of KMnO₄

The moles required of KMnO₄ are:

27.50cm³ * (1dm³ / 1000cm³) = 0.0275dm³ * (0.100mol / dm³) = 0.00275mol KMnO₄

Moles of Fe²⁺ are:

0.00275mol KMnO₄ * (5 moles Fe²⁺ / 1mol KMnO₄) = 0.01375moles of Fe²⁺

In grams (Molar mass Fe: 55.845g/mol):

0.01375moles of Fe²⁺ * (55.845g/mol) =

And percentage is:

0.768g Fe / 2.000g * 100 =

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:

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:

This question perplexes me somewhat. If we as humans are not able to detect a scent or odor from certain substances, that does not of necessity mean those substances are not giving off an odor, and are therefore not “truly” odorless, just odorless to the less sensitive noses of humans.

Water is supposedly odorless, but I know quite well of a test where subjects did a blind tasting, only instead of wine these people were tasting Australian waters, sourced from different locations around the country.

All of these tasters (professionals) were able to differentiate the waters and from what I recall, were all accurate. These wine buffs use their palates as well as their taste-buds, so, were there no odor, their task would have had a greater degree of difficulty.

My own baby sister has such a sensitive palate that she can tell you if you serve her a glass of water from the fridge whether that water was fresh, straight from the tap (unfiltered), filtered or had been boiled before and whether it had been boiled for more than five minutes or not. Truly.

So I would find it difficult to answer your question, “What substances are truly odorless?” , because I am not sure of the criteria you mean by “truly” odorless. In other words, If you are talking about zero degrees, are you talking of the freezing point of water, absolute zero or zero degrees Kelvin?

I’m sure there are substances that are odorless, to humans, but are those same substances “truly” odorless, or only to our perception of them?

Hope this helps, have a wonderful day/night, and stay safe!

Answer:

true mass is based on gravity

Answer:

true

Explanation:

mass based on gravity

Answer:

do you have a picture of the choices?

Answer:

i think iron

Explanation:

i not sure with my ans

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:  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:

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)