endothermic and exothermic would appreciate the help

Answer:

i think the answer is... A

Answer:

B

Explanation:

the group number is=valence electrons. element 1 is in group 1 element 18 is in group 8. 1<8

Answer:

the answer is b

Explanation:

i just know

Answer:

0.17 moles

Explanation:

In the elements of the periodic table, the atomic mass = molar mass. Ex: Atomic mass of Carbon is 12.01 amu which means molar mass of Carbon is also 12.01g/mol.

In order to find the # of moles in a 12 g sample of NiC-12, we will need to multiply the number of each atom by its molar mass and then add the masses of both Nickel and C-12 found in the periodic table:

Since there's just one atom of both Carbon and Nickel, we just add up the masses to find the molar mass of the whole compound of NiC-12.

There's 12g of NiC-12, which is less than the molar mass of NiC-12, so the number of moles should be less than 1. In order to find the # of moles in NiC-12, we need to do some dimensional analysis:

P.S. C-12 or C12 just means that the Carbon atom has an atomic mass of 12amu and a molar mass of 12g/mol, or just regular carbon.

Answer:

W=ma

=0.7×9.8

=6.86N

....................

PLEASE GIVE BRAINLIEST

Answer:

1 mol. = 0.169 mol He.

Complete Question:

Which statement is true about air temperature and humidity?

Group of answer choices.

a. the air temperature does not affect how much moisture the air can hold

b. hotter air holds less moisture than colder air.

c. hot air and cold air share the same amount of moist.

d. colder air holds less moisture than hotter air.

Answer:

d. colder air holds less moisture than hotter air

Explanation:

Weather can be defined as the atmospheric conditions of a particular area over a short period of time.

The elements of weather include precipitation, wind, temperature, atmospheric pressure, relative humidity, cloud, and wind speed.

Temperature can be defined as a measure of the degree of coldness or hotness of a physical object (body).

On the other hand, humidity refers to the concentration (amount) of water vapor that is present in the air. It is high when there's a lot of water vapor in the air and low when the level of water vapor is small.

Hence, the true statement about air temperature and humidity is that colder air holds less moisture than hotter air because as the air cools, its molecules move closer together while the molecules move farther apart as the air become hot.

Additionally, at constant humidity, relative humidity is inversely proportional to temperature i.e as the temperature decreases, relative humidity increases.

Answer: colder air holds less moisture than hotter air

Explanation:

Answer:

Explanation:

From the information given:

We can say that the rate of reaction is utilized to decide the reaction speed, and it is subject to the rate constant.

The power of concentration related to the rate equation can be said to be the order of the reaction.

For zero-order reaction: it is the reaction whose rate is free and not dependent on the reactant's concentration.  

Concentration-time reaction is given as;

[tex]\mathbf{[A] = [A_o] -kt ---- (1)}[/tex]

where;

t = time

k = rate constant

A_o = initial concentration of reactant

Thus, the plot between [A] and t needs to be a straight line.

On the other hand, The First order reaction is the reaction whose rate is straightforwardly corresponding to the reactant's concentration.  

Its concentration-time relation can be expressed as,

[tex]\mathbf{In([A])= In ([A_o])-kt ---- (2)}[/tex]

t = time

k = rate constant

[A_o] = initial concentration of the reactant

Then, the plot between [A] & t requires to be a straight line.

Presently, the plot between ln([A]) vs time appears to be in a straight line with the slope of the line equivalents to the rate constant (k).

hence,

slope = -k

Then;

[tex]\mathbf{k = -slope ---- (3)}[/tex]

Now; to discover the activation energy we need to utilize Arrhenius relation which is given as,

[tex]\mathbf{In(k) = In(K_o) - \dfrac{E_o}{RT} ---- (4)}[/tex]

From the above equation;

k_o = arrhenius parameter

Ea = activation energy

R = 8.314 J/mol.K

T = temperature in Kelvin

From the data given  for concentration vs time;

t[min]      Ca(mol/L)

0                      2

5                     1.6

9                     1.35

15                   1.1

22                    0.87

30                    0.7

40                    0.53

60                    0.35

a)

Since we can deduce the order of the reaction,

Let's assume that it is a zero-order reaction, Thus, the plot of Ca vs t can be seen in the first image attached below;

From the diagram, it is clear and obvious that it is NOT a straight line.

Thus, we conclude that this order is NOT a zero-order.

However, let also assume that order is first order,

Now, from the second diagram showing the plot of ln(Ca) vs t, we can deduce that it is a straight line which implies that it is the order of the reaction is first order.

Therefore, the equation for the first order is given as;

[tex]\mathbf{In([A]) = In ([A_o])- kt}[/tex]

Recall that: the slope of the ln(A) v/s time will result in a rate constant,

Thus, from the graph we have;

slope = -0.0289 mol/L.min and:

slope = - k

Hence;

rate constant = k = 0.0289 mol/L.min and the order = 1st order

b)

On the off chance that we need to take more data points, we will like to take the data point in the scope of 40 min to 60 min time interval, on the grounds that the significant deviation is seen there. more information focuses will imply more accuracy.

Answer:

it's b.

Explanation:

thank u so much for this. i appreciate it. lol.

Answer: The first plastic based on a synthetic polymer was invented in 1907.  Plastic sticks around in the environment for ages, threatening wildlife and spreading toxins.

Answer:

the answer is d

Explanation:

top right corner

Answer:

and can cause changes in motion. Inertia.

Explanation:

Answer:  change its motion.

Explanation: hope this helps :)

Answer:

266.3 g

Explanation:

The balanced reaction is:

First we convert 2.3 moles of AlPO₄ to moles of Li₃PO₄, using the stoichiometric coefficients:

Then we convert Li₃PO₄ moles into grams, using its molar mass:

Answer: The concentration of this solution is [tex]114g/dm^3[/tex]

Explanation:

Concentration of a solution is defined as the number of grams of solute dissolved per liter of the solution.

Given : mass of solute = 28.4 g

volume of solution = [tex]250cm^3=0.25dm^3[/tex]      [tex]1cm^3=0.001dm^3[/tex]  

[tex]Concentration=\frac{28.4g}{0.25dm^3}=114g/dm^3[/tex]

Thus the concentration of this solution is [tex]114g/dm^3[/tex]

By definition and change of units, the concentration of this solution is 113.6 [tex]\frac{grams}{dm^{3} }[/tex].

Chemical concentration determines the ratio of solute and solvent in a chemical solution and is defined as the ratio of the amount or volume of solute to the amount of solution. The more solute, the higher the concentration in a solution.

In this case, you know:

mass of solute= 28.4 g

volume of solution= 250 cm³= 0.25 dm³ (being 1 cm³= 0.001 dm³)

Then, the concentration can be calculated as:

[tex]concentration= \frac{28.4 grams}{0.25 dm^{3} }[/tex]

Concentration= 113.6 [tex]\frac{grams}{dm^{3} }[/tex]

Thus the concentration of this solution is 113.6 [tex]\frac{grams}{dm^{3} }[/tex].

Learn more about concentration:

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Answer: human induced global warming

Explanation:

It’s the only one that makes sense if you read the question

Answer:

idfk man but someone will HELP

Explanation:

Answer:

4.0561×0.03÷63.5= 0.001916 mol cu

A coin is 3.00% Cu by mass. If the mass of the coin is 4.0561g, moles of Cu does it contain 0.001916 mole of Cu.

It is the most fundamental characteristic of matter and one of the fundamental quantities in physics.

Mass is a term used to describe how much matter is there in a body. The kilogramme is the SI unit of mass (kg). A body's mass does not alter at any point in time.

Given mass of coin = 4.0561g , moles =? , Cu by mass= 3.00%

4.0561×0.03÷63.5= 0.001916 mole Cu.

Thus, A coin is 3.00% Cu by mass. If the mass of the coin is 4.0561g, moles of Cu does it contain 0.001916 mole of Cu.

To learn more about mass, refer to the below link:

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Answer:

Explanation:

-Reactants-

C: 1

O: 3

H : 2

-Products-

C: 6

O: 8

H: 12

Since these two are not equal, this reaction is not balanced.

Here is the balanced reaction:

6CO2+6H2O ⇒ C6H12O6+6O2

Answer:

I think a red flower with one part colored yellow

Explanation:

a red flower with one part colored yellow

This reaction is different in that the carbon undergoes an incomplete combustion as opposed to complete combustion where carbon is fully oxidized. A caveat: incomplete combustion products in general can be difficult to predict without sufficient information, as it's not uncommon to obtain a mixture of different products.

Here, we are told that solid carbon is burned in limited air to produce a gas. I am presuming that, in the equation that's given, the "0" represents a blank where you must fill in a chemical symbol. In this case, our equation would be: 2C(s) + O₂(g) → 2CO(g).

There is not enough information here to provide the numerical answers to the two questions. From the words in the question (e.g., "is different" and "this time"), it would seem that this question is an excerpt from a larger or preceding question where specific numbers had been provided or computed.

However, it's possible to make some general observations on how one may go about answering these questions if one had more information.

Since we're to assume that oxygen is the limiting reagent, if one is given the amount of solid carbon (either in mass, moles, or number of atoms), it's possible to determine the moles of CO(g) that's produced since C and CO have an equal stoichiometric ratio. So, for example, if one burns 2 moles of C(s), then 2 moles of CO(g) would be produced.

But, there is still not enough information to compute the volume of CO gas if this is the line of questioning. We don't know, for instance, the temperature or pressure of the reaction conditions. In fact, the only way it would be possible to answer this would be if you were given beforehand a conversion factor that relates the volume of CO(g) to its quantity (e.g., to assume that one mole of gas occupies x liters).

As for the second question, this would depend on what you know about the quantity of the C(s) reacted and/or the quantity (or volume, from question a) of CO(g) produced. If you can get the number of moles of C(s) reacted or CO(g) produced, the number of moles of O₂(g) used up: It would be half the number of moles of C(s) reacted or half the number of moles of CO(g) produced). Again, it's impossible to determine the volume of O₂(g) using just the information provided here, so I suspect that you must have further information relating gas quantity to volume. As we did with CO(g), the volume of O₂(g) used up can be found using whatever conversion factor you have.

If you have any further information or questions, please feel free to follow up.  

This reaction is distinct in that the carbon undergoes incomplete combustion rather than complete combustion, in which the carbon is completely oxidized. incomplete combustion products in general can be difficult to predict without sufficient information, as a mixture of different products is not uncommon.

Combustion is a chemical reaction in which a substance reacts with oxygen to produce heat. Combustible refers to a substance that can be burned. It is also known as a fuel. The fuel can be either solid, liquid, or gas.

We're told that solid carbon is burned in a small amount of air to produce a gas.

This would be determined by the amount of C(s) reacted and/or the amount (or volume, from question a) of CO(g) produced. If you can calculate the number of moles of C(s) reacted or CO(g) produced, you can calculate the number of moles of O2(g) consumed: It would be half the amount of C(s) reacted or half the amount of CO(g) produced).

Thus, This reaction is distinct in that the carbon undergoes incomplete combustion rather than complete combustion.

To learn more about combustion, follow the link;

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Answer:

1. troposphere

2. less dense/decreases

3. ozone

4. nitrogen

5. xylem

6. flagellum

7. kingdom fungi

8. Ocean convection currents

9. As they fly, insects spread pollen that sticks to their bodies from the flowers.

10. the plastic handle, because it is a good insulator.

11. The hyphae, or feeding structures, reach deep into the wood to obtain nutrients

12. chemical energy

13. created or destroyed.

14. electromagnet

15. c

16. kinetic, elastic potential

Answer: 90 degrees        .

Answer:

it decreases

Explanation:

because its false

Answer:

True

Explanation:

The pressure will increase because the heat will make the molecules move around and spread out more.

If you want I could go into more detail with the explanation.

Answer:

Eukarya

Explanation:

Organisms in the domain Eukarya keep their genetic material in a nucleus and include the plants, animals, fungi, and protists.

☁️ Answer ☁️

annyeonghaseyo!

Your answer is:

it can bond with oxygen to form rust or iron oxide. and it can bond with carbon to form steel.

Here's another one: Iron bonds with lots of things: Oxygen (Ferric Oxide = rust),Chlorine (Ferric Chloride]), Fluorine, ... , even other Iron (in aMetallic Bond or crystal).

Hope it helps.

Have a nice day hyung/noona!~ ￣▽￣❤️