I just need the answer please to both if you can

Answer:

b

Explanation:

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

Answer: [tex]1.94\times 10^{-3}g[/tex] of NaOH

Explanation:

pH or pOH is the measure of acidity or alkalinity of a solution.

pH is calculated by taking negative logarithm of hydrogen ion concentration.

[tex]pH=-\log [H^+][/tex]

Putting in the values:

[tex]10.020=-\log[H^+][/tex]

[tex][H^+]=9.55\times 10^{-11}[/tex]

[tex][H^+][OH^-]=10^{-14}[/tex]

[tex][OH^-]=\frac{10^{-14}}{9.55\times 10^{-11}}=1.05\times 10^{-4}M[/tex]

[tex]NaOH\rightarrow Na^++OH^-[/tex]

[tex]Molarity=\frac{moles\times 1000}{\text {Volume in ml}}[/tex]

[tex]1.05\times 10^{-4}M=\frac{moles\times 1000}{463ml}[/tex]

moles = [tex]4.86\times 10^{-5}[/tex]

Mass of [tex]NaOH=moles\times {\text {Molar mass}}=4.86\times 10^{-5}\times 40=1.94\times 10^{-3}g[/tex]

Thus [tex]1.94\times 10^{-3}g[/tex] of NaOH is needed to prepare 463 mL of solution with a pH of 10.020

Answer:

c

Explanation:

Answer:

the answer is 0

The answer to the question is

A. 0

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

Learn more: https://brainly.com/question/24848191

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:

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:

Your answer is D. It is the heat required to change a gram of substance from a liquid to a gas.

Answer:

c

Explanation:

Answer:

Li has fewer protons than Li+

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:

The   answer is wavelength

Explanation:

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:

the red moon occurs during lunar eclipse

Explanation:

The reddish coloration arises because sunlight reaching the Moon must pass through a long and dense layer of Earth's atmosphere, where it is scattered

Answer:

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

hope it helps!

Answer:

around 0.283

Explanation:

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:

Electrical energy

Explanation:

Electrical energy is caused by the moving of electrons.

hope it helps!

Answer:

NeHe

Explanation:

Atomic Mass: 24.182302

Number: 18

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

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.

the carbon cycle is the process in which carbon travels from the atmosphere into organisms and the earth and then back into the atmosphere

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:

A. 82.2g of KClO3

B. Word equation:

50g of KCl react with 50g of O2 to produce 82.2g of KClO3

C. Formula equation:

2KCl + 3O2 —> 2KClO3

Explanation:

The balanced equation for the reaction. This is given below:

2KCl + 3O2 —> 2KClO3

Next, we shall determine the masses of KCl and O2 that reacted and the mass of KClO3 produced from the balanced equation. This is illustrated below:

Molar Mass of KCl = 39 + 35.5 = 74.5g/mol

Mass of KCl from the balanced equation = 2 x 74.5 = 149g

Molar Mass of O2 = 16x2 = 32g/mol

Mass of O2 from the balanced equation = 3 x 32 = 96g

Molar Mass of KClO3 = 39 + 35.5 + (16x3) = 122.5g/mol

Mass of KClO3 from the balanced equation = 2 x 122.5 = 245g

Summary:

From the balanced equation above:

149g of KCl reacted.

96g of O2 reacted.

245g of KCl were produced.

Next, we shall determine the limiting reactant. This is illustrated below:

From the balanced equation above,

149g of KCl reacted with 96g of O2.

Therefore, 50g of KCl will react with = (50 x 96)/149 = 32.21g of O2.

Since a lesser mass of O2 ( i.e 32.21g) than what was given (i.e 50g) is needed to react completely with 50g of KCl, therefore, KCl is the limiting reactant and O2 is the excess reactant.

A. Determination of the mass of KClO3 produced from the reaction.

In this case the limiting reactant will be used.

From the balanced equation above,

149g of KCl reacted To produce 245g of KClO3.

Therefore, 50g of KCl will react to produce = (50 x 245)/149 = 82.2g of KClO3.

Therefore, 82.2g of KClO3 is produced from the reaction.

B. Word equation:

50g of KCl react with 50g of O2 to produce 82.2g of KClO3.

C. Formula equation:

2KCl + 3O2 —> 2KClO3

The mass of [tex]\rm KClO_3[/tex] produced has been 82.1085 g.

The word equation for the reaction has been: 50 gram potassium chloride reacts with 50 g oxygen to give 82.1085 g potassium chlorate.

The formula equation has been, [tex]\rm 2\;KCl\;+\;3\;O_2\;\rightarrow\;2\;KClO_3[/tex].

The balanced chemical equation for the reaction has been given as:

[tex]\rm 2\;KCl\;+\;3\;O_2\;\rightarrow\;2\;KClO_3[/tex]

From the balanced chemical equation, 2 moles of KCl reacts with 3 moles of oxygen to give 2 moles of [tex]\rm KClO_3[/tex].

The moles of reactants have been given as:

[tex]\rm Moles=\dfrac{mass}{molar\;mass}[/tex]

The moles of 50 g KCl has been given as:

[tex]\rm Moles\;KCl=\dfrac{50}{74.55} \\Moles\;KCl=0.67\;mol[/tex]

The moles of KCl available has been 0.67 mol.

The moles of 50 g [tex]\rm O_2[/tex] has been given as:

[tex]\rm Moles\;O_2=\dfrac{50}{32}\\Moles\;O_2=1.5625\;mol[/tex]

The moles of 50 g [tex]\rm O_2[/tex] has been 1.5625 mol.

From the balanced equation, for 2 moles KCl, 3 moles oxygen has been required. For 0.67 mol KCl, oxygen required has been:

[tex]\rm 2\;mole\;KCl=3\;moles\;O_2\\0.67\;mol\;KCl=\dfrac{3}{2}\;\times\;0.67\;mol\;O_2\\0.67\;mol\;KCl=1.005\;mol\;O_2[/tex]

The available moles of oxygen has been 1.5625 mol. Thus, oxygen has been excess reactant and KCl has been limiting reactant.

The moles of [tex]\rm KClO_3[/tex] produced has been given as:

[tex]\rm 2\;mol\;KCl=2\;mol\;KClO_3\\0.67\;mol\;KCl=\dfrac{2}{2}\;\times\;0.67\;mol\;KClO_3\\0.67\;mol\;KCl=0.67\;mol\;KClO_3[/tex]

The moles of [tex]\rm KClO_3[/tex] produced has been 0.67 mol.

The mass of [tex]\rm KClO_3[/tex] produced has been:

[tex]\rm Mass=Moles\;\times\;molar\;mass\\Mass\;KCl=0.67\;\times\;122.55\;\\Mass\;of\;KCl=82.1085\;g[/tex]

The mass of [tex]\rm KClO_3[/tex] produced has been 82.1085 g.

The word equation for the reaction has been:

50 gram potassium chloride reacts with 50 g oxygen to give 82.1085 g potassium chlorate.

The formula equation has been, [tex]\rm 2\;KCl\;+\;3\;O_2\;\rightarrow\;2\;KClO_3[/tex].

For more information about chemical equation, refer to the link:

https://brainly.com/question/13350862

Answer:

[tex]\frac{1}{6}[/tex]

Explanation:

Molar ratio is defined as the ratio of number of moles of reactants or products in a balanced chemical equation.

In this balanced equation, the number of C6H6 molecules react to form 12 CO2 molecules.

Thus, the molar ratio between C6H6 to  carbon will be equal to 2 moles of  C6H6 divided by 12 moles of CO2

[tex]\frac{2}{12}\\\frac{1}{6}[/tex]

Answer:

Dark matter also called baronic matter is the matter that makes up 27% of the universe.

In 1933 it was determined as that mass that cannot be seen, that is, the non-visible mass of outer space.

Dark matter also plays a central role in the formation of structures and the evolution of galaxies and has measurable effects on the anisotropy of cosmic microwave background radiation. The composition of this matter is unknown today.

The dark matter component has considerably more mass than the "visible" component of the Universe.

Explanation:

There are certain researchers who say that the appearance of dark matter was before the appearance of the big bang.

A relevant fact of this matter is that dark matter exerts gravity, and that gravity affects the movements of objects.

Despite the fact that nothing is known about its origin, astronomers have amply demonstrated that dark matter plays a determining role in the formation of galaxies and galactic clusters, which could not maintain their cohesion without its existence, but many doubt that it is the remainder / remnant or product of a big bang.

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:

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