Please please help me please please help please please help me please please help please please help me please

Answer:

C. 21%oxygen

Explanation:

Dry air contains 78.09% nitrogen, 20.95%oxygen, 0.93% argon, 0.04% carbon dioxide, and small amounts of other gases.

Answer:

Budding, in biology, a form of asexual reproduction in which a new individual develops from some generative anatomical point of the parent organism. ... The initial protuberance of proliferating cytoplasm or cells, the bud, eventually develops into an organism duplicating the parent.

Explanation: im not sure if this will help because you didnt give any statements.

Answer: Cell division with mitosis causes new individuals to develop on a parent.

Explanation: did the test A.P.E.X. hope this helps <3

Answer:

0.62 N

Explanation:

first of all: 3.0 s = 0.05 m

Let ? be the work that brakes do at 3.0s

24 m ----> 299 N

0.05 m ---->?

? = (0.05 m x 299 N)/ 24

? = (14.95)/ 24

? = 0.622 N

Answer:

it is 25%

Explanation:

Answering so you can give the other person brainliest :D have a good day

Answer:

[Fe⁺³] = 0.0010 M

[SCN⁻] = 0.0006 M

Explanation:

First we calculate how many moles of Fe⁺³ and SCN⁻ were added, using the given volumes and concentrations:

Now we can calculate the initial concentrations, after calculating the new volume of the solution:

Answer:

The Florian predict the metamorphic rocks because it changes when subjected to heat and pressure.

Explanation:

i hope this helps

Answer:

ch4+h2o----725°-->co+2h2

Answer:

a. 6 moles of O₂

b. 4.06×10²⁴ molecules of O₂

c. 3.04 g of KCl

Explanation:

Reaction of decomposition is:

2KClO₃  →  2KCl  +  3O₂

a. See stoichiometry value

2 moles of potassium chlorate can decompose to 2 moles of potassium chloride and 3 moles of oxygen. Ratio is 2:3

If 2 moles of KClO₃ can decompose to 3 moles of O₂

Then 4 moles, may decompose to (4 . 3)/2 = 6 moles of O₂

b. In this case, the stoichiometry is the same.

Per 2 moles of KClO₃, I produce 2 moles of KCl

Then, 4.5 moles of KCl, were produced by 4.5 moles of KClO₃

We apply, the last relation:

(4.5 . 3) /2 = 6.75 moles of O₂ are also produced.

How many molecules are in 6.75 moles?

6.75 mol . 6.02×10²³ molecules/mol = 4.06×10²⁴ molecules of O₂

c. First of all, we convert the mass to moles:

5g . 1mol /122.55g = 0.0408 moles of salt

As ratio is 2:2, 0.0408 moles of salt, decompose to 0.0408 moles of KCl

We convert the moles to mass: 0.0408 mol . 74.55g /mol = 3.04g

Answer and Explanation:

V1/n1 = V2/n2

450.0 mL / 0.0184 mol = 200.0 mL / n2

n2 = 8.17X10^-3 mol

moles removed = 0.0184-8.17X10^-3 = 0.0102 mols removed, I think I'm right but I'm not 100% sure..

According to Avogadro's law, 0.008 moles of gas must be removed to shrink balloon to 200 ml.

Avogadro's law is a gas law which states that the total number of atoms or molecules has a direct proportion to the volume occupied by a gas at a constant temperature and pressure.

It is closely related to ideal gas equation as it links temperature, pressure, volume and the amount of substance.It is given as, V∝n,

The straight line graph of volume versus moles is a straight line passing through the origin which implies that zero moles of gas occupy zero volume.

Here, the number of moles is calculated as, V₁/n₁=V₂/n₂

Therefore on substitution, n₂=0.0184×200/450=0.008 moles.

Thus,0.008 moles are required to shrink  the balloon to 200 ml.

Learn more about Avogadro's law,here:

https://brainly.com/question/6534668

#SPJ3

Answer:

[tex]Cs^+[/tex]

Explanation:

Cesium Lewis dot structure would look like this:

·Cs,  because it only has one valence electron. But, since it has a plus, that means we lost an electron. So, we have to get rid of the dot and you have:

[tex]Cs^+[/tex]

based on the law of conservation of energy its it atoms hold by strong chemical bonds

Answer:

The correct answer is - b) precipitation.

Explanation:

In the given question the lead ion in an aqueous solution is mixed with the Leutium ion in an aqueous solution and forms an insoluble or solid salt. This type of reaction is referred to as precipitation reactions in chemistry.

Such reactions are helpful in determining if a particular ion is present in the solution or not.

Pb2+ (aq) + lu- (aq) → Pblu (s)

Answer:

hope this helps

Explanation:

72

Answer:

The particles' kinetic energy is increased, allowing the gas to expand. When a gas is heated the volume will increase when gas is increased....

Answer:

mass of CO 2 = M r x number of moles of CO 2 = 44.0 × 0.010 = 0.44 g

Explanation:

Answer:

1 and the element is hydrogen (there is an exception for the octet rule for the element hydrogen) hope this helps

Explanation:

Answer:

3

Explanation:

Answer:

The answer is 28.68 moles

Explanation:

Hope this helped Mark BRAINLEST!!!

The mass of ammonia prepared from 24.5 kg magnesium nitride, according to the reaction Mg₃N₂(s) + 6H₂O(l) → 3Mg(OH)₂(s) + 2NH₃(g), knowing that the process is 71% efficient is 5.87 kg.

The balanced reaction of production of ammonia is:

Mg₃N₂(s) + 6H₂O(l) → 3Mg(OH)₂(s) + 2NH₃(g)   (1)

First, let's find the number of moles of magnesium nitride

[tex] n_{Mg_{3}N_{2}} = \frac{m_{Mg_{3}N_{2}}}{M_{Mg_{3}N_{2}}} [/tex]  (2)

Where:

[tex]m_{Mg_{3}N_{2}}[/tex]: is the mass of Mg₃N₂ = 24.5 kg

[tex]M_{Mg_{3}N_{2}}[/tex]: is the molar mass of Mg₃N₂ = 100.9494 g/mol

The number of moles is (eq 2):

[tex] n_{Mg_{3}N_{2}} = \frac{m_{Mg_{3}N_{2}}}{M_{Mg_{3}N_{2}}} = \frac{24500 g}{100.9494 g/mol} = 242.70 \:moles [/tex]

We can calculate the mass of ammonia prepared, knowing that 1 mol of Mg₃N₂ reacts with 6 moles of H₂O to produce 3 moles of Mg(OH)₂ and 2 moles of NH₃ (reaction 1).

[tex]n_{NH_{3}} = \frac{2\: moles\: NH_{3}}{1\: mol\: Mg_{3}N_{2}}*n_{Mg_{3}N_{2} = \frac{2\: moles\: NH_{3}}{1\: mol\: Mg_{3}N_{2}}*242.70 \:moles \:Mg_{3}N_{2} = 485.4 \:moles[/tex]

Then, the mass of NH₃ is:

[tex] m_{NH_{3}} = n_{NH_{3}}*M_{NH_{3}} = 485.4 \:moles*17.031 g/mol = 8266.8 g = 8.27 kg [/tex]

Since the process is 71% efficient, the mass that can be prepared is:

[tex] m = 8.27 kg*0.71 = 5.87 kg [/tex]

Therefore, the mass of ammonia that can be prepared is 5.87 kg.

I hope it helps you!

Answer:

3.5 mol

Explanation:

Step 1: Given data

Moles of HCl: 7.0 mol

Step 2: Write the balanced equation

Fe(s) + 2 HCl(aq) ⇒ FeCl₂(aq) + H₂(g)

Step 3: Calculate the moles of H₂ gas produced from 7.0 moles of HCl

According to the balanced equation, the molar ratio of HCl to H₂ is 2:1.

7.0 mol HCl × 1 mol H₂/2 mol HCl = 3.5 mol H₂

Answer: The order of increasing energy is: radio < infrared < red < blue < UV < x rays

Explanation:

Electromagnetic wave is defined as the wave which is associated with both electrical and magnetic component associated with them.  

The electromagnetic radiations consist of gamma rays , X rays , Ultraviolet , Visible , Infra red , microwaves and radio waves arranged in order of decreasing frequency and increasing wavelengths. The visible region consists of violet , indigo , blue , green , yellow, orange and red lights in order of decreasing frequency or increasing wavelength

The relationship between energy  and frequency of the wave follows the equation:

[tex]E=h\times \nu[/tex]

where,

[tex]\nu[/tex] = frequency of the wave

E = energy of wave

From the above relation, it is visible that energy and frequency follow direct relation. For increase in value of frequency, energy increases and vice-versa.

Thus the order of increasing energy is: radio < infrared < red < blue < UV < x rays

Answer:

2 PO₄³⁻(aq) + 3 Fe²⁺(aq) ⇒ Fe₃(PO₄)₂

Explanation:

Let's consider the complete ionic equation between the ions present. It includes all the ions and the insoluble compounds (Fe₃(PO₄)₂ is insoluble).

Na⁺(aq) + 2 PO₄³⁻(aq) + 3 Fe²⁺(aq) + NO₃⁻(aq) ⇒ Fe₃(PO₄)₂ + Na⁺(aq) + NO₃⁻(aq)

The net ionic equation includes only the ions that participate in the reaction (not spectator ions) and the insoluble compounds.

2 PO₄³⁻(aq) + 3 Fe²⁺(aq) ⇒ Fe₃(PO₄)₂

Answer:

Nitrogen

Explanation:

Answer:

Yes, its nitrogen. I wrote my answer earlier in the wrong spot.

Explanation:

The atmosphere contains many gases, most in small amounts, including some pollutants and greenhouse gases. The most abundant gas in the atmosphere is nitrogen, with oxygen second. Argon, an inert gas, is the third most abundant gas in the atmosphere.

Answer:

electrons are transferred from the clouds to the grounf

Explanation:

Answer:

the answer is circle 3 hope it helps

Answer:

e. oxygen is a reactant in combustion and pure oxygen increases the reactant concentration

Explanation:

The reaction of a burning match is combustion. In this combustion, the organic components of the match (such as cellulose, C₆H₁₀O₅) react with oxygen, producing water and carbon dioxide:

Seeing as oxygen is a reactant and not a catalyst nor product, and that nitrogen plays no part in the reaction, the only correct answer is option e.