why can mosquitos stand on water?
A-The mosquito is able to walk on the water due to the attraction between multiple water molecules, creating surface tension.
B-The mosquito is able to walk on the water due to the attraction between water molecules and other non-water molecules, creating surface tension.

Answer:

A. The number of atoms of each element is the same on the reactant side as the product side.

Explanation:

The equation demonstrates the law of conservation of mass in such a way that the number of atoms of each element is the same on the reactant side as the product side.

According to the law of conservation of mass "matter is neither created nor destroyed in a chemical reaction but they are changed from one form to another".

Answer:

A. Nucleus

Nucleus is the answe

Answer:

It kinda helps but not  really

Thanks for trying anyway doe!

Explanation:

Explanation:

1)

2Fe+3Cl2 →2FeCl3

2)

CH4+2O2 → CO2 +2H2O

3)

SnO2+2H2 →2H2O +Sn

4)

2KOH + H2SO4 → K2SO4+2H2O

Answer:

Nitrogen and Oxygen make up 99% of the Earths atmosphere. Then Argon makes up the rest of the atmosphere.

Answer:

0.967mole

Explanation:

Given parameters:

Volume of NH₄Cl  = 21.67L

Unknown:

Number of moles  = ?

Solution:

If we assume that the volume was taken at standard temperature and pressure,

 Then;

  Number of moles  = [tex]\frac{volume }{22.4L}[/tex]  

 Number of moles  = [tex]\frac{21.67}{22.4}[/tex]   = 0.967mole

Answer:

1)2kclo3=2kcl+3o2

2)2NaCl+F2=2NaF+cl2

3)Pb(OH)2+2HCl=2H2O+PbCl2

4)2Albr3+3k2so4=6kbr+al2(so4)3

5)CH4+2O2=CO2+2H2O

Explanation: cirrocumulus

Answer:

Dissolving sugar in water, burning paper, and melting gold are all chemical changes

Explanation:

The action cannot be reversed, or undone. Therefore it is a chemical change.

Boiling water is a physical change.

Answer:

4.00L

Explanation:

Using Charle's law, which have the following equation:

V1/T1 = V2/T2

Where;

V1 = initial volume (litres)

T1 = initial temperature (Kelvin)

V2 = final volume (litres)

T2 = final temperature (Kelvin)

According to the information provided, T1 = 275K, T2 = 400K, V1 = ?, V2 = 5.82L

Hence, using the formula;

V1/275 = 5.82/400

400 × V1 = 275 × 5.82

400V1 = 1600.5

V1 = 1600.5 ÷ 400

V1 = 4.001

Therefore, volume of the gas before it is heated is 4.00L

Answer:118

Explanation: it’s right

Answer:

118 elements

Hope that helps

Answer:

6.944 liters of O₂ at STP will react with 8.7 grams of C₂H₄ to form CO₂ and H₂O.

Explanation:

The balanced reaction is:

C₂H₄ + 3 O₂ ⇒ 2 CO₂ + 2 H₂O

Being the molar mass of the elements:

Then the molar mass of compound C₂H₄ is:

C₂H₄= 2*12 g/mole + 4*1 g/mole= 28 g/mole

By stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction), 1 mole of C₂H₄ acts. Then, being the mass of a mole of a substance, which can be an element or a compound, 1 mole of C₂H₄ is 28 g, which is the amount of mass that reacts in this case.

Then be able to apply the following rule of three: if by stoichiometry 28 grams of C₂H₄ react with 3 moles of O₂, 8.7 grams of C₂H₄ with how many moles of O₂ do they react?

[tex]moles of O_{2} =\frac{8.7 grams ofC_{2} H_{4}*3 moles of O_{2} }{28grams ofC_{2} H_{4}}[/tex]

moles of O₂= 0.31  

The STP conditions refer to the standard temperature and pressure. Pressure values at 1 atmosphere and temperature at 0 ° C are used and are reference values for gases. And in these conditions 1 mole of any gas occupies an approximate volume of 22.4 liters.

Then we can apply the following rule of three: if by definition of STP 1 mole occupies 22.4 L, 0.31 moles how much volume will it occupy?

[tex]volume=\frac{0.31 moles*22.4 L}{1 mole}[/tex]

volume= 6.944 L

6.944 liters of O₂ at STP will react with 8.7 grams of C₂H₄ to form CO₂ and H₂O.

The volume of O₂ at STP that will react with the given C₂H₄ is 20.8 L

First, we will determine the number of moles of O₂ required.

From the given balanced chemical equation,

C₂H₄ + 3O₂ → 2CO₂ + 2H₂O

This means

1 mole of C₂H₄ is required to react completely with 3 moles of O₂

Now, we will determine the number of moles of C₂H₄ present

Mass of C₂H₄ = 8.7 g

Using the formula

[tex]Number\ of\ moles = \frac{Mass}{Molar\ mass}[/tex]

Molar mass of C₂H₄ = 28.05 g/mol

∴ Number of moles of C₂H₄ = [tex]\frac{8.7}{28.05}[/tex]

Number of moles of C₂H₄ = 0.31016 mole

Since

1 mole of C₂H₄ is required to react completely with 3 moles of O₂

Then,

0.31016 mole of C₂H₄ will react completely with 3 × 0.31016 mole of O₂

3 × 0.31016 = 0.9305 mole

∴ Number of moles of O₂ required is 0.9305 mole

Now, for the volume of O₂ at STP that will react

Since 1 mole of a gas occupies 22.4 L at STP

Then,

0.9305 mole of O₂ will occupy 0.9305 × 22.4 L at STP

0.9305 × 22.4 = 20.8432 L

≅ 20.8 L

Hence, the volume of O₂ at STP that will react with the given C₂H₄ is 20.8 L

Learn more here: https://brainly.com/question/15209655

Answer:

Di Sulphur tetraiodide is the chemical compound with the formula S2I4

Explanation:

Answer:

B. 3+

Explanation:

When Fe²⁺ loses an electron, it becomes an Fe³⁺ ion.

   The loss of an electron in an atom makes the atom becomes positively charged. Further losing electrons makes the atom more positive.

 For the given ion;

 Fe²⁺   if it loses an electron more, it becomes Fe³⁺.

The expression is given as:

         Fe²⁺    →    Fe³⁺  +  e⁻

Moles of Carbon dioxide : n = 4.037 x 10⁻³

Given

2.43 x 10²¹ molecules of Carbon dioxide

Required

Moles

Solution

1 mol = 6.02 x `10²³ particles(molcules, atoms, ions)

Can be formulated :

N = n x No

n = moles

No = Avogadro's number 6.02 x `10²³

moles of Carbondioxide :

n = N/No

n = 2.43 x 10²¹ / 6.02 x `10²³

n = 4.037 x 10⁻³

Answer:

Antonie van Leeuwenhoek used single-lens microscopes, which he made, to make the first observations of bacteria and protozoa. His extensive research on the growth of small animals such as fleas, mussels, and eels helped disprove the theory of spontaneous generation of life.

Explanation:

Hope this helps and have a great day :)

Answer:

diet soda has artificial sugar and regular soda has insane amounts of sugar

Answer:

Explanation:

(1) The primary industry is mainly agriculture, which includes agricultural, forestry, animal husbandry and fishery components. Agriculture is the foundation of social economy. (2) The secondary industry, which mainly includes the industrial and construction industries.

Answer:

SiH4

Explanation:

4 hydrogens serve a the base and the Si is on top which forms a tetrahedral shape.

Answer:

The answer is chlorine

Explanation:

Answer:

False

Explanation:

I took the quiz and got it right

Answer:

percent yield = 80.7%

Theoretical yield of silver sulfide = 30.975 g

Actual yield  = 25 g

Explanation:

Given data:

Mass of silver = 27 g

Mass of silver sulfide formed = 25 g

Theoretical yield of silver sulfide = ?

Actual yield = ?

Percent yield = ?

Solution:

Chemical equation:

2Ag + S   →     Ag₂S

Number of moles of Ag:

Number of moles = mass/molar mass

Molar mass of silver = 107.8 g/mol

Number of moles = 27 g/ 107.8 g/mol

Number of moles = 0.25 mol

Now we will compare the moles of silver with silver sulfide.

               Ag         :       Ag₂S

               2            :         1

              0.25        :      1/2×0.25 = 0.125 mol

Theoretical yield of silver sulfide:

Mass = number of moles × molar mass

Mass = 0.125 mol ×  247.8 g/mol

Mass = 30.975 g

Actual yield is given in question = 25 g

Percent yield:

Percent yield = (actual yield / theoretical yield) × 100

Percent yield = (25 g/ 30.975 g ) × 100

percent yield = 80.7%

Answer:

H₂O₂

Explanation:

Hydrogen peroxide is a typical example of a compound molecule. A compound is made up of one or more atoms that are combined together in a definite grouping.

The properties of a compound is different from those of the elements that combines to from them.

Answer:

Ethanol has a higher octane number than gasoline, providing premium blending properties, according to the U.S.

Explanation:

Department of Energy. Minimum octane number requirements prevent engine knocking and maintain drivability.

Answer:

The answer is D

I searched it up to verify.

Answer: I think the possible answer is B or D

Explanation: There are few of the energies like: Gravitational, electrical, Chemical.....

Explanation:

moles=mass÷molar mass

n=m÷Mr

6.0=14.6÷Mr

Mr=14.6÷6.0

Molar mass= 2.433

Answer:

68.6 °C

Explanation:

From conservation of energy, the heat lost by acetone, Q = heat gained by aluminum, Q'

Q = Q'

Q = mL where Q = latent heat of vaporization of acetone, m = mass of acetone = 3.33 g and L = specific latent heat of vaporization of acetone = 518 J/g

Q' = m'c(θ₂ - θ₁) where m' = mass of aluminum = 44.0 g, c = specific heat capacity of aluminum = 0.9 J/g°C, θ₁ = initial temperature of aluminum = 25°C and θ₂ = final temperature of aluminum = unknown

So, mL = m'c(θ₂ - θ₁)

θ₂ - θ₁ = mL/m'c

θ₂ = mL/m'c + θ₁

substituting the values of the variables into the equation, we have

θ₂ = 3.33 g × 518 J/g/(44.0 g × 0.9 J/g°C) + 25 °C

θ₂ = 1724.94 J/(39.6 J/°C) + 25 °C

θ₂ = 43.56 °C + 25 °C

θ₂ = 68.56 °C

θ₂ ≅ 68.6 °C

So, the final temperature (in °C) of the metal block is 68.6 °C.

The final temperature of the metal block is 74.97°C

The specific heat of a substance is the required quantity of heat needed to raise the temperature of 1 gram of the substance by 1° C.

From the parameters given:

The number of moles of acetone is:

[tex]\mathbf{= 3.33 g \times \dfrac{mol}{58.08 \ mol}}[/tex]

= 0.0573 mol

At standard conditions, the heat of vaporization of acetone is:

[tex]\mathbf{\Delta H = 32.0 \ kJ/mol \times 0.0578 \ mol } \\ \\ \mathbf{\Delta H = 1.8496 \ kJ } \\ \\ \mathbf{ \Delta H = 1.85 \times 10^3 \ J}[/tex]

Given that:

The specific heat of the aluminum is = 0.903 J/g° C

The heat energy can be computed as:

q = msΔT

q = 41 g × 0.903 J/g° C × (x - 25°C)

Using the calorimetry principle, heat energy lost by metal = heat energy gained by acetone.

i.e.

[tex]\mathbf{q_{(acetone)} gain = q_{(metal)} lost }[/tex]

[tex]\mathbf{-1.85 \times 10^3 \ J = - 41 g \times 0.903 \ J/g^0 C \times ( x - 25^0 c) }[/tex]

[tex]\mathbf{1.85 \times 10^3 \ J = 41 g \times 0.903 \ J/g^0 C \times ( x - 25^0 c) }[/tex]

[tex]\mathbf{(x - 25 ^0 C) = \dfrac{1.85 \times 10^3 \ J }{ 41 g \times 0.903 \ J/g^0 C}}[/tex]

[tex]\mathbf{(x - 25 ^0 C) = 49.97^0 C}}[/tex]

[tex]\mathbf{x = 49.97^0 C+25 ^0 C}}[/tex]

x = 74.97 °C

Learn more about specific heat here:

https://brainly.com/question/1430612

Answer:

18.3%

Explanation:

Add the numbers together, and then take the number of grams of the substance, in this case copper, not coppper lol. divide the .45 by 2.45 to get 18.3