Please help I don’t understand

Answer:

1 mole Of Helium = Weight of Helium/4Weight of Helium = 1*4 = 4 grams 1 mole of Helium contains 6.023*10²³ ( Avogadro number) atoms. Number of moles of in 4 grams of Hydrogen 4 grams is = given weight / molecular weight of Hydrogen (H₂) = 4/2 =2 Number of atoms/molecules in 2 moles of Hydrogen is (2*6.023*10²³) atoms. = 12.046*10²³ atoms.

(Hope this helps)

The number of atoms in 2 moles of helium is 1.204×10²⁴ atoms

From Avogadro's hypothesis,

1 mole of any substance = 6.02×10²³ atoms

Thus,

1 mole of helium = 6.02×10²³ atoms

With the above information in mind, we can obtain the number of atoms in 2 moles of helium as follow:

1 mole of helium = 6.02×10²³ atoms

Therefore,

2 moles of helium = 2 × 6.02×10²³ atoms

2 moles of helium = 1.204×10²⁴ atoms

Thus, we can conclude that 2 moles of helium contains 1.204×10²⁴ atoms

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Answer:

Propane

Explanation:

From the question given, we were told that 0.1240 kg of propane reacted with excess oxygen to produce 0.3110kg of carbon dioxide.

Since the reaction took place in the presence of excess oxygen, therefore, propane is the limiting reactant as all of it is used up in the presence of excess oxygen.

Answer:

The limiting reactant is propane, C₃H₈ and the percentage yield is 83.77%

Explanation:

Mass of propane = 0.1240 kg = 124 g

Mass of carbon dioxide = 0.3110 kg = 311 g

Molar mass of propane = 44.1 g/mol

Molar mass of carbon dioxide = 44.01 g/mol

Number of moles of propane = 124/44.1 = 2.812 moles

Number of moles of carbon dioxide = 311/44.01 = 7.067 moles

Equation for the reaction

C₃H₈ + 5O₂ → 3CO₂ + 4H₂O

Hence 1 mole of propane ideally yields 3 moles of CO₂

Hence, 2.812 moles of propane will yield 3×2.812 moles = 8.44 moles of CO₂

Since, oxygen is in excess, therefore, the limiting reactant = Propane, C₃H₈

The percentage yield = 7.067/8.44× 100 = 83.77%.

Answer:

el nino: the boy

la nina: the girl

Explanation:

Answer:

el nino is dinosour la nino is fishcat

Explanation:

Answer:

Option "D" is the correct answer to the following question:

Explanation:

Magnets usually have their pulling properties, which we call magnetic power.

A major feature of magnetic power is that the closer the magnets are brought together, the higher the magnetic force increases.

On increasing distance, the magnetic force starts to decrease.

So, we can say that students should bring magnets closer to each other to increase the magnetic power.

Answer:

The Sun powers life on Earth; it helps keep the planet warm enough for us to survive. It also influences Earth’s climate: We know subtle changes in Earth’s orbit around the Sun are responsible for the comings and goings of the past ice ages. But the warming we’ve seen over the last few decades is too rapid to be linked to changes in Earth’s orbit, and too large to be caused by solar activity

Explanation:

Answer:

Hey!

Your answer is 45kg.m/s

Explanation:

Using the formula P=M x V

(p=momentum...M=mass...V=velocity)

We do M x V

15 x 3

Which gives us an answer of 45kg.m/s!

HOPE THIS HELPS!!

Answer:

Limiting reactant is CS2

% yield = 131.8 %

Explanation:

Using the alanced equation given, Mole ratio of C to CS2 is 1 : 5.

That is, for every 1 mole of CS2 used, 5 moles of Carbon is produced.

35g of CS2 --- [tex]\frac{35}{76.14}[/tex] moles

= 0.4597 moles

⇒ mass of C produced = 5 × 0.4597 × 12 g/mol

= 27.6 g of C.

Percentage yield (%) = [tex]\frac{actual- yield}{theoretical- yield}[/tex]

= [tex]\frac{36.4}{27.6} * 100[/tex] =131.9%

Answer:Most cars have the visible outer panel, and supporting structure, made from steel. Some use aluminium, at least one series-produced model had magnesium doors, and there are also doors where the visible parts are plastic or fiberglass, with some sort of metal inside for strength.

Explanation:

Answer:

Most cars have the visible outer panel, and supporting structure, made from steel. Some use aluminium, at least one series-produced model had magnesium doors, and there are also doors where the visible parts are plastic or fiberglass, with some sort of metal inside for strength.

Answer:

0 °C and 1 Atm,

Explanation:

Standard Temperature and Pressure. Standard temperature is equal to 0 °C, which is 273.15 K.

Standard Pressure is 1 Atm, 101.3kPa or 760 mmHg or torr

Answer:

The correct answer is  

[CH4][H2O]/[CO][H2]3

Option 3 is correct

Explanation:

Step 1: Data given

For the equation aA + bB ⇆ cC + dD

The equilibrium constant is [C]^c * [D]^d / [A]^a*[B]^b

Step 2: Calculate the equilibrium constant Kc

CO+3H2⇌CH4+H2O

Kc = [H2O][CH4] / [CO][H2]³

The correct answer is  

[CH4][H2O]/[CO][H2]3

Option 3 is correct

Answer:

B. 5.6 × 10^-10

Explanation:

The Kb for the acetate ion can be obtained from; Kb = [CH3COOH] [OH-]/[CH3COO-]

The term Kb refers to the base dissociation constant of a substance. We know that the Kb for the acetate ion can be obtained from;

Kb = [CH3COOH] [OH-]/[CH3COO-]

The numerical value of the Kb can be obtaned if we have the concentrations of the various species in the equation above.

Learn more about Kb: https://brainly.com/question/19165803

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Answer:

Li has fewer protons than Li+

Hey there!

P₄ + Cl₂ → PCl₃

First, let's balance Cl.

There are 2 on the left, and 3 on the right.

To balance this, let's put a coefficient of 3 in front of Cl₂ and a coefficient of 2 in front of PCl₃.

P₄ + 3Cl₂ → 2PCl₃

Now we have 6 on the left and 6 on the right.

Next, let's balance P.

There are 4 on the left and 2 on the right.

Let's change the coefficient in front of PCl₃ from 2 to 4.

P₄ + 3Cl₂ → 4PCl₃

There are now 4 P on each side.

However, now Cl is unbalanced, with 6 on the left and 12 on the right.

We can change the coefficient in front of Cl₂ from 3 to 6.

P₄ + 6Cl₂ → 4PCl₃

So now, we have 4 P on each side and 12 C on each side.

This is our final balanced equation.

Hope this helps!

Answer:

1:1

Explanation:

Took test

Answer:

Water, and other neutral

Explanation:

That means those substances have pH = 7.

When the amount of H+ is more than the amount of OH- in solution, the substance is acidic ( eg.: Lemon juice ). pH < 7

When the amount of H+ is less than the amount of OH- in solution, the substance is basic ( eg.: Baking soda ). pH > 7

Answer:

C

Explanation:

The answer is always C

Answer:C. Concave mirror

Explanation:

When the surface of a mirror curves inward, like the inside of a bowl, it is called c. Concave mirror.

Answer:

the answer is 0

The answer to the question is

A. 0

Answer:

heat = 229139.43 cal

Explanation:

given data

specific heat of iron is 0.107 cal/g-°C     C = 0.4494 J/g°C;

Mass of iron = 24.7 kg = 24700 g

temperature T1 = 880°C

temperature T2 = 13°C

solution

we know that Heat lost that is express as

heat loss = mcΔT      .........................1

here m is the mass and c is specific heat capacity of iron and ΔT is the change in temperature

so here change in the temperature is = 880°C - 13°C

change in the temperature = 867°C

so put here value and we get

heat  = 24700 × 0.107 cal/g-°C × 867°C

heat = 229139.43 cal

Answer:

b

Explanation:

Electromagnetic waves are waves that have no medium to travel whereas mechanical waves need a medium for its transmission.

Answer:

NeHe

Explanation:

Atomic Mass: 24.182302

Number: 18

I don't know, I just made it up.

Answer:

Electrical energy

Explanation:

Electrical energy is caused by the moving of electrons.

hope it helps!

Answer:

4. 1HCL + 1NAOH- I NACL+1H2O

Explanation:

there is 2 hydrogens on the left side of the equation, balancing out to the other side of the equation. everything else would be balanced out too

Answer:

365nm and Exothermic reaction

Explanation:

b) The Einstein Planck's equation states that

E = hf where E is the energy of a photon

                     h  is the Planck's constant

                     f  is the frequency

But Frequency f = c/λ  where c  is the speed of light

                                                  λ  is the wavelength

Therefore Energy E = hc/λ

From the above equation we see that the Energy of a photon is indirectly proportional to its wavelength

Hence as the wavelength increases from 365nm to 435nm, the energy of the photons decreases

Therefore, a photon will wavelength 365nm would have a higher energy than one will wavelength of 435nm.

c) From the diagram we observe the following:

At high temperatures,   HPR⁺ occurs at a higher concentration than at low temperatures.

At low temperatures, more of PR⁻ is formed than at high temperatures

The equation of the reaction is

HPR⁺ (aq) ⁺ ⇆ H⁺ + PR⁻(aq)      

Le Chartelier's principle states that when an external constraint such as a change in concentration, pressure or temperature is placed on a system in equilibrium, the system acts in such a way as to oppose the change.

Hence a decrease in temperature on the side of reactant, HPR would force the equilibrium to the side of the products, PR in other to accommodate the change

The forward reaction, which produces more of the product PR⁻ is exothermic because  the at low temperatures, the the forward reaction is favoured and equilibrium shifts to the right.

Answer:

around 0.283

Explanation:

Answer:

The   answer is wavelength

Explanation:

Answer:

Volume = 5.73L

Explanation:

Data;

V1 = 3.75L

P1 = 0.980atm

P2 = 0.641atm

V2 = ?

This question involves the use of Boyle's law, which states that, the volume of a fixed mass of gas is inversely proportional to its pressure provided that temperature remains constant.

Mathematically,

V = kP, k = PV

P1V1 = P2V2 =P3V3=........=PnVn

P1V1 = P2V2

V2 = (P1 * V1) / P2

V2 = (0.980 × 3.75) / 0.641

V2 = 5.73L

The final volume of the gas is 5.73L

Answer:

CH3−CO−O−CH3

Explanation:

i just took the test

Answer:

2 carbon atoms/molecules are present on the reactant side.

hope it helps!

Answer:

c

Explanation: