What are the answers to these?

Answer:

The amount of CaCO₃ Jeeves needs to find is approximately 71.392 grams

Explanation:

The given parameters are;

The mass of the CaO required = 40 g

The chemical reaction for the production of CaO from CaCO₃ is given as follows;

CaCO₃(s) → CaO(s) + CO₂(g)

Therefore, 1 mole of CaCO₃ produces 1 mole of CaO and 1 mole of CO₂,

The molar mass of CaO = 56.0774 g/mol

Number of moles, n = Mass/(Molar mass)

The number of moles of CaO = 40 g/(56.0774 g/mol) ≈ 0.7133 moles of CaO

Therefore, given that 1 mole of CaO is produced from 1 mole of CaCO₃ 0.7133 moles of CaO will be produced from 0.7133 moles of CaCO₃

The molar mass of CaCO₃ = 100.0869 g/mol

Mass = The number of moles × The molar mass

∴ The mass of CaCO₃ Jeeves needs to find = 0.7133 moles × 100.0869 g/mol ≈ 71.392 g

The mass of CaCO₃ Jeeves needs to find ≈ 71.392 grams.

Answer:  The correct answer is:  " 0.54 g " .

__________________________________________

Explanation:

Note that "hydrogen gas" is:  

H₂ (g)  ;   that is:  a "diatomic element" (diatomic gas) ;

_________________________________________

The molecular weight of "H" is:  1.00794 g ;

   (From the Periodic Table of Elements).

So, the molecular weight of:  H₂ (g)  is:

    " 1.00794 g * 2  = 2.01588 g ; {use calculator) ;

_________________________________________

Note the conversion for a gas at STP:

______

  1 mol of a gas = 22.4 L gas;

___

i.e. " 1 mol / 22.4 L " ;

____

So:     " 5.7 L H₂ (g)  [tex]* \frac{1 mol H_{2} }{22.4 L} *\frac{2.01588 g}{mol} =? ;[/tex]

The "L" ("literes" cancel out to "1" ;  since "L/L = 1 ;

The "mol" (moles) cancel out to "1" ; since "mol/mol = 1 ;

____

and we are left with:

____

 [5.7 * 2.104588 g ] / 22.4  =  ?  g ;

______________________

→ [ 11.9961516  g ] / 22.4 =

          0.53554248214  g ;l

_____________________________

We round this value to:  " 0.54 g " ;

 → since "5.7 L " has 2 (two) significant figures;  

     22.4 is an exact number conversion;

     and "5.7 L" has fewer significant figures than:

    " 2.104588 " ; or:  " 1.00794 " .

  → as such: We round to "2 (two) significant figures."

______________________________

Hope this is helpful.  Wishing you the best in your academic endeavors!

_______________________________

Answer:

The dolphins average speed is 3.51 [tex]\frac{meters}{seconds}[/tex]

Explanation:

First of all, the following rules of three should be applied:

[tex]distance=\frac{20 miles*1609 meters}{1 mile}[/tex]

distance=32,180 meters

[tex]time=\frac{153 minutes*60 seconds}{1 minute}[/tex]

time= 9,180 seconds

Speed ​​is a physical quantity that expresses the relationship between the space traveled by an object and the time used for it. That is, speed implies the change of position of an object in space within a certain amount of time and is calculated as:

[tex]speed=\frac{distance}{time}[/tex]

So in this case the velocity is calculated as:

[tex]speed=\frac{32,180 meters}{9,180 seconds}[/tex]

Solving, you get:

Speed= 3.51 [tex]\frac{meters}{seconds}[/tex]

The dolphins average speed is 3.51 [tex]\frac{meters}{seconds}[/tex]

Answer:

The symbol that represent a salt is CaCl2

Explanation:

The CaCI2 is the calcium chloride that an organic compound now a salt having a chemical formula i.e. CaCI2. Also it is non-color cyrstalline solid at the room temperature also it is highly soluble in the water

Therefore as per the given situation the symbol that represent a salt is CaCI2

This is the answer and the same is not provided in the given options

Pair of compounds have the same empirical formula :C₂H₂ and C₆H₆

Given

Carbon compound

Required

The same empirical formula

Solution

The empirical formula is the smallest comparison of atoms of compound forming elements.  

A molecular formula is a formula that shows the number of atomic elements that make up a compound.  

(empirical formula) n = molecular formula  

C₂H₂ and C₆H₆

Empirical formula CH

(CH)₂=C₂H₂

(CH)₆=C₆H₆

C₂H₆ and C₃H₈

C₂H₆: Empirical formula CH₃

C₃H₈: Empirical formula C₃H₈

C₂H₅OH and CH₃OH ⇒ Empirical formula

CH₃CHO: Empirical formula : CH₃CHO

CH₃COOH: Empirical formula CH₂O

Answer:

1. Broadly, there are three different methods for how electricity is generated in the United States. They include; Fossil fuels, Nuclear energy, and Renewable energy sources.

2. Fossil fuels, are used the most, with Natural gas topping the list by 38%.

3. More should be invested into renewable gas. It is a clean source of energy and investing in it would bring about a cleaner and safer environment.

Explanation:

Fossil fuels arise from plants and animals that have been long dead and can can now be converted to sources of energy. Examples include; coal natural gas, crude oil. etc.  

Nuclear energy arises from the fission of uranium atoms, nuclear decay, and nuclear fusion. They are safe since green house gases are not emitted. Thermal energy can be generated as the byproduct of these reactions.

Renewable sources of energy are generated from natural sources which are always available. Examples are; sun, wind, biomass, water, and geothermal sources,

Answer:

B. 9

Explanation:

The formula of the compound is given as:

            9NaCl

Coefficient is the number before the compound. The compound here is made up of sodium and chlorine.

Therefore, we have 9 as the coefficient and it is 9 moles of NaCl.

Note, NaCl is an ionic compound.

Osmosis is of two types:

Endosmosis– When a substance is placed in a hypotonic solution, the solvent molecules move inside the cell and the cell becomes turgid or undergoes deplasmolysis. This is known as endosmosis.

Exosmosis– When a substance is placed in a hypertonic solution, the solvent molecules move outside the cell and the cell becomes flaccid or undergoes plasmolysis. This is known as exosmosis.

There are some variations or types of osmosis on the basis of the direction of the movement of solvent molecules.

Answer:

Sound waves travel through matter

Explanation:

Higher amplitude sound waves are more likely to be transmitted through matter instead of reflected. Lower amplitude sound waves are more likely to be reflected or absorbed, resulting in a lack of an echo. Sound can travel through air, water, and solids

Answer:

A) Abosrbed

Explanation:

The change is endothermic, meaning the material absorbs energy when it changes its phase from a solid to a liqiud.

Answer:

Option D. Decomposition reaction

Explanation:

MgBr₂ (s) —> Mg (s) + Br₂ (l)

To know which option is correct. It is important that we have an understanding of what each option means.

1. Synthesis reaction: This is a type of reaction in which two different elements react to produce a new compound different from the two elements that reacted. e.g

A + D —> AD

2. Combustion reaction: This is a reaction which involves a compound and oxygen to produce carbon dioxide (CO₂) and water (H₂O) e.g methane (CH₄) undergoes combustion reaction as follow:

CH₄+ 2O₂ —> CO₂ + 2H₂O

3. Single Replacement reaction: This is a reaction in which one element replaces or displaces another element in a single compound. This is illustrated below:

X + WZ —> XZ + W

We can see that the X replaces W in the reaction.

4. Decomposition reaction: This is a type of reaction in which a compound decompose or breaks into two or more simple compounds or elements e.g

ZX₄ —> Z + 4X

From the above illustrations, we can conclude that the the reaction:

MgBr₂ (s) —> Mg (s) + Br₂ (l)

Is a decomposition reaction because MgBr₂ breakdown into Mg and Br₂

Answer:

0.4 km/h  velocity is also the direction their going, in this case the person, that I'll name billy bob joe, is going in so yeh

Explanation:

give me brainliest?

Answer:

C) hydrogen bonds

Explanation:

The abnormally high boiling point of HF compared to HCl is primarily due to the intermolecular forces called hydrogen bonds.

Hydrogen bonds are intermolecular forces of attraction between polar molecules in which a hydrogen atom is directly joined to a highly electronegative atom (oxygen, nitrogen or fluorine).

Hydrogen bonds are very strong force of attraction compared to dipole - dipole attraction that holds the HCl together.

Answer:

I think It's C

Explanation:

due to higher waves can get easy transfers and receive those signals for most things, such as radios, TVs, phone signals etc etc

The use of high-frequency radio waves, a beneficial technological advancement for humans because they travel over longer distances.

The frequency of a repeated event is its number of instances per unit of time. In certain cases, it is also referred to as temporal frequency or ordinary frequency to underline differences with spatial and angular frequencies, respectively.

The number of waves that pass a specific place in a predetermined period of time is known as the wave frequency. The hertz (Hz) is the SI unit for wave frequency, where 1 hertz is equivalent to 1 wave crossing a fixed point in 1 second.

The vibrations that created the wave had the same frequency as the wave itself. For instance, you need to move a rope up and down faster to produce a wave with a greater frequency.

Thus, option C is correct.

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Answer:

When our tear film becomes unstable, symptoms of Dry Eye can occur. OUR TEAR FILM HAS THREE LAYERS. Our tear film is made up of three layers – an oil (lipid) layer, a water (aqueous) layer and a mucin layer. ... Its main purpose is to seal the tear film which helps reduce evaporation of our natural tears.

Balanced equation :

2Al +6HCI⇒ 3H₂ + 2AlCI₃

Given

Reaction (unbalanced)

Al +HCI⇒ H₂ + ALCI₃

Required

Balanced equation

Solution

Give a coefficient

aAl +bHCI⇒ cH₂ + AlCI₃

Al, left = a, right=1⇒a= 1

Cl, left = b, right=3⇒b=3

H, left = b, right=2c⇒b=2c⇒3=2c⇒c=3/2

The equation becomes :

Al +3HCI⇒ 3/2H₂ + AlCI₃ x 2

2Al +6HCI⇒ 3H₂ + 2AlCI₃

Answer:

there are 12 hydrogen atoms in 2 molecules of C3H6

Explanation:

Answer:

you didnt show a picture, but if it just exposed then it will probably be a physical change

Explanation:

Answer:

D

Explanation:

You need both, independant and dependant variables for a hypothesis.

Answer:

9.64g/mL

Explanation:

Given parameters:

Mass of the metal  = 106g

Volume of cylinder = 50mL

Volume difference  = 31mL  - 20mL  = 11mL

Unknown:

Density of the metal  = ?

Solution:

To find the density of the metal, we use;

 Density  = [tex]\frac{mass}{volume}[/tex]  

 Density  = [tex]\frac{106}{11}[/tex]   = 9.64g/mL

Answer:

All except a diamond

Explanation:

The helium in the balloon has mass it fills the space its in.

The neon-filled tube has mass because it takes up space.

Water in a glass has mass because the water is taking up space.

A diamond does not because it does not take up space.

The chemical formula for copper (II) phosphate is Cu₃(PO4)₂. The charge on each copper ion is +3. Therefore, option E is correct.

The term chemical formula is defined as the constituent components of a compound together with the number of atoms in each element's smallest unit, such as a molecule or formula unit.

Given a chemical formula, we may name simple compounds by using the names of the components and a few simple principles.

The simplest whole-number ratio of the atoms in a compound is demoed by empirical formulae, the number of each type of atom in a molecule is shown by molecular formulas, and the bonds between the atoms in a molecule are shown by structural formulas.

The charge on each copper ion is +3,the subscripts balance the electrical charge.

Thus, option E is correct.

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Answer:

Hello  there!

The first answer is hot

The second answer is sunshine!

Explanation:

Those make the most sense

Have a great day!

Answer:

bran fart is kewl

Explanation:

yes

Answer:

Gases, liquids, and solids are all made up of atoms, molecules, and/or ions, but the behaviors of these particles differ in the three phases. Gas is well separated with no regular arrangement. liquid are close together with no regular arrangement. solid are tightly packed, usually in a regular pattern.

Explanation:

Answer:

premium: 91 octane rating

Explanation:

Octane number refers to the percentage or volume fraction of isooctane in a fuel.

The octane number gives a picture of how safe a fuel is for an engine. The higher the octane rating the lesser the tendency of the fuel to cause knocking of the engine.

The type of gasoline with the highest percentage of octane among the options is premium.

Answer:

Electrical and magnetic

You exert a gravitational force on the pupil and the pupil exerts an equal gravitational force on you. ... The size of the gravitational force depends on the mass of the objects involved. The greater the mass, the greater the gravitational force.

Explanation:

Answer:

2Fe(s) + 3O2(g) --------> 2FeO3(s)

Explanation:

According to the question, a  battery was used  to light the steel wool by bringing the terminals very close together. When  the battery came into contact with the steel wool, current was sent out through the thin wire.  This caused the iron to heat up quite well.

Iron reacts with oxygen under these conditions as follows;

2Fe(s) + 3O2(g) --------> 2FeO3(s)

This is the chemical reaction that occurs when the steel wool is set on fire.

Chemical equation involved in Dr. Jeff's demonstration is

2 Fe+3 O₂[tex]\rightarrow[/tex]2 FeO₃

Battery is a device which helps in conduction of current. When a battery is used to pass a current through  a substance in this case which is steel wool made up of iron it starts getting heated up.

The amount by which substance gets heated up is directly proportional to the current passing through it. As more current is passed through the battery it gets heated more.

During heating, the iron present in the steel wool reacts with oxygen to form iron oxide with iron present in the+3 oxidation state.When the heat exceeds a certain point the steel wool catches fire due to the heat generated. The  heat causes the electrons present in steel wool of iron to move faster and collide with each other  thus generating more heat.

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Answer:

fire

Explanation:

Answer:

ants if you splash a ant with sum water that shít is dead