Plz help me it’s emergency

Answer:

pH = 1

pH = 3

pH = 5

pH = 9

pH = 11

pH = 13

Explanation:

The pH is defined as log [H⁺]. HCl in solution produce H⁺. That means HCl concentration is equal to H⁺ concentration. Thus:

- 0.1M HCl. pH = -log 0.1 = 1

- 0.001M HCl. pH = -log 0.001 = 3

- 0.00001M HCl. pH = -log 0.00001 = 5

For a base that produce OH⁻ in solution you can define a pOH as pOH = -log [OH⁻] knowing (For water equilibrium) pH = 14 - pOH

Thus, for the NaOH solutions:

- 0.00001M NaOH: pOH = -log 0.00001M = 5. pH = 14 - 5 = 9

- 0.001M NaOH: pOH = -log 0.001M = 3. pH = 14 - 3 = 11

- 0.00001M NaOH: pOH = -log 0.1M = 1. pH = 14 - 1 = 13

Answer:

pH = 1

pH = 3

pH = 5

pH= 7

pH = 9

pH = 11

pH = 13

Explanation:

Just did the test :)

Answer:

The statement is false.

Explanation:

Quasars are astronomical objects that are very luminous found in the centres of dome galaxies and powered by gas spiraling at high velocity into an extremely large black hole. However, Nebula/Nebulae is a giant cloud of dust, hydrogen, helium and other ionized gases found in space. It is sometimes called "star nurseries"

I hope this helps you :)

Answer:

[tex]\large \boxed{35.6 \,^{\circ}\text{C}}[/tex]

Explanation:

There are two heat transfers involved: the heat lost by the granite and the heat gained by the water.

According to the Law of Conservation of Energy, energy can neither be destroyed nor created, so the sum of these terms must be zero.

Let the granite be Component 1 and the water be Component 2.

Data:  

For the granite:

[tex]m_{1} =\text{75.0 g; }T_{i} = 92.5 ^{\circ}\text{C; }\\C_{1} = 0.790 \text{ J$^{\circ}$C$^{-1}$g$^{-1}$}[/tex]

For the water:

[tex]m_{2} =\text{60.0 g; }T_{i} = 22.2 ^{\circ}\text{C; }\\C_{2} = 4.184 \text{ J$^{\circ}$C$^{-1}$g$^{-1}$}[/tex]

Calculations

(a) The relative temperature changes

[tex]\begin{array}{rcl}\text{Heat lost by granite + heat gained by water} & = & 0\\m_{1}C_{1}\Delta T_{1} + m_{2}C_{2}\Delta T_{2} & = & 0\\\text{75.0 g}\times 0.790 \text{ J$^{\circ}$C$^{-1}$g$^{-1}$} \times\Delta T_{1} + \text{60.0 g} \times 4.184 \text{ J$^{\circ}$C$^{-1}$g$^{-1}$}\Delta \times T_{2} & = & 0\\59.25\Delta T_{1} + 251.0\Delta T_{2} & = & 0\\\end{array}[/tex]

(b) Final temperature of water

[tex]\Delta T_{1} = T_{\text{f}} - 92.5 ^{\circ}\text{C}\\\Delta T_{2} = T_{\text{f}} - 22.2 ^{\circ}\text{C}[/tex]

[tex]\begin{array}{rcl}59.25(T_{\text{f}} - 92.5 \, ^{\circ}\text{C}) + 251.0(T_{\text{f}} - 22.2 \, ^{\circ}\text{C}) & = & 0\\59.25T_{\text{f}} - 5481 \, ^{\circ}\text{C} + 251.0T_{\text{f}} - 5572 \, ^{\circ}\text{C} & = & 0\\310.2T_{\text{f}} - 11052\, ^{\circ}\text{C} & = & 0\\310.2T_{\text{f}} & = & 11052 \, ^{\circ}\text{C}\\T_{\text{f}}& = & \mathbf{35.6 \, ^{\circ}}\textbf{C}\\\end{array}\\\text{The final temperature is $\large \boxed{\mathbf{35.6 \,^{\circ}}\textbf{C}}$}[/tex]

Answer:

B).  Allow efficient gathering of unobservable phenomena.

Explanation:

Surveys are described as the method of gathering information from a specified group of respondents for purposes like research or assessment of the truth of thoughts or opinions associated with a process.

As per the question, one of the most considerable benefits of the survey is that 'it allows the efficient gathering of unobservable phenomena'. The data associated with phenomena like stated preferences, behaviors, beliefs, and factual information are unobservable and can not be collected through observation but surveys help in doing so as well as in the assessment of the validity or reliability of the existing propositions about such phenomena. Thus, option B is the correct answer.

Answer: b

Explanation:

Answer:

google gotchu i promise

Answer:

hydrogen has the atomic number of 1

Answer:

Water is necessary for life because water carries nutrients to all of our cells. Water also carries oxygen to the brain and allows our body to absorb minerals and vitamins

Explanation:

hope this helps! good luck :)

Answer:

Explanation:

1. lithium=Li

2.berilium=Be

3.carbon=C

4.Lithium= Li1+

The elements with their symbols and charge are:

1. Lithium, Li, charge is 1.

2. Beryllium, Be, charge is 2+

3. Carbon, C

4. Lithium, Li, charge is 1+

Chemical elements are the base of everything present on the Earth. These elements are present under the earth.

There are 118 elements traced and are present in either free or mixed form.

Thus, the correct options are 1. Lithium, Li, charge is 1.

2. Beryllium, Be, charge is 2+

3. Carbon, C

4. Lithium, Li, charge is 1+

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Answer:

Heat can travel from one place to another in three ways: Conduction, Convection and Radiation. Both conduction and convection require matter to transfer heat.  Conduction is the transfer of heat between substances that are in direct contact with each other. Thermal energy is transferred from hot places to cold places by convection. Radiation is a method of heat transfer that does not rely upon any contact between the heat source and the heated object as is the case with conduction and convection. Heat can be transmitted through empty space by thermal radiation often called infrared radiation.

The thermal energy transfer may take place within the iguana’s enclosure through Conduction, Convection, and Radiation.

In conduction, heat transfer happens between objects by direct contact. If the heat transfer takes within the fluid then it is In convection. In radiation, heat transfers without involving particles through electromagnetic waves.

In conduction, Heat transfer occurs because of the difference in temperature. In convection, heat transfer occurs due to the difference in density. In radiation, heat transfer occurs with a temperature greater than 0 K  in all objects.

In convection, heat transfer in conduction is slow while in convection, heat transfer, in convection is faster and in radiation, the heat transfer in radiation is the fastest.

Conduction and convection heat transfer does not follow the law of refraction and reflection. Radiation heat transfer follows the law of refraction and reflection.

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Answer:

A scale, or a weight. Both of which are more scientifically referred to as a balance.

The answer is a Balance

Answer:

The probability of finding the particle somewhere in the universe must be equal to 1.

Answer:

Rises, sinks

the correct answer is B

Answer:

rises, sinks

Explanation:

Hot magma rises because as the temperature increases, it expands and becomes less dense. As it reaches the top, it cools down and becomes more dense, which means it will sink. Therefore, hot magma rises and cool magma sinks in convection mantle mechanism.

Answer:

1.2 mol/L

Explanation:

Molarity = mol solute/L solution

We can accept that

L solution = L water = 2.5 L.

Molarity = 3 mol/2.5 L = 1.2 mol/L

1.2 mol/L is the molarity of a solution of HCl if 3 moles dissolved in 2.5 liters of water.

Molarity (M) is defined as the number of moles of solute dissolved in 1 L of solution. Molarity is also known as Molar concentration. The S.I Unit of Molarity is molar (M) or mol/L.

Molarity (M) = [tex]\frac{\text{Mass of solute}}{\text{Volume in liters}}[/tex]

                   =  [tex]\frac{3\ mol}{2.5\ L}[/tex]

                   = 1.2 mol/L

Thus, we can say that 1.2 mol/L is the molarity of a solution of HCl if 3 moles dissolved in 2.5 liters of water.

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The element that would behave most likely magnesium is calcium. The correct option is b.

An element is a material whose atoms all contain the same number of protons: that is, all atoms of each element have the same amount of protons.

Elements are the most basic chemical forms and thus cannot be broken down chemically.

A chemical element is something that cannot be broken down further through any chemical reaction. Every element's atom encompasses a distinct number of protons.

A pure element is defined in chemistry as a substance whose atoms all (or almost all) have the same atomic number, or number of protons.

Beryllium and Calcium exhibit chemical reactions similar to Magnesium.

Thus, the correct option is b.

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Answer:

possibly two

Explanation:

you said Jonathan had hybrid eyes, did you mean that he was heterozygous? if so 2 out of 4 will have the recessive gene "blue".

Answer:

NH4+

Explanation:

HNO3 + NH3 = NH4+ + NO3-

HNO3 = H+

Conjugate means "to join together" when used in chemistry

Acids are solutions with a higher ratio  of H+ ions to OH- ions.

Answer:

D. Kb = 1.8 × 10⁻⁵  

Explanation:

The strongest base has the largest Kb value.

The largest Kb value has the smallest negative exponent.

So, the strongest base has Kb = 1.8 × 10⁻⁵.

The value of base dissociation constant (Kb) which represents the strongest base is 1.8×10⁻⁵.

Strong bases are those bases which completely dissociates into their ions and have high pH value in between 7 and 14.

pH value of any base is directly proportional to the value of base disssociation constant (Kb), means high value of Kb will indicates high value of pH i.e. hing basic strength. So, highest value of Kb is 1.8×10⁻⁵.

Hence 1.8×10⁻⁵ Kb value shows strong base.

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Answer:

–500KJ

Explanation:

Data obtained from the question include the following:

Heat of reactant (Hr) = 800KJ

Heat of product (Hp) = 300KJ

Enthalphy change (ΔH) =..?

The enthalphy change is simply defined as the difference between the heat of product and the heat of reactant i.e

Enthalphy change = Heat of product – Heat of reactant

ΔH = Hp – Hr

With the above formula, we can easily calculate the enthalphy change as follow

ΔH = Hp – Hr

ΔH = 300 – 800

ΔH = –500KJ.

Therefore, the overall energy change for the reaction between hydrogen and oxygen shown in the diagram above is –500KJ

Answer : The theoretical yield in grams for this reaction under the given conditions is, 8.28 grams.

Explanation : Given,

Mass of [tex]H_2[/tex] = 1.46 g

Mass of [tex]N_2[/tex] = 10.5 g

Molar mass of [tex]H_2[/tex] = 2 g/mol

Molar mass of [tex]N_2[/tex] = 28 g/mol

First we have to calculate the moles of [tex]H_2[/tex] and [tex]N_2[/tex].

[tex]\text{Moles of }H_2=\frac{\text{Given mass }H_2}{\text{Molar mass }H_2}[/tex]

[tex]\text{Moles of }H_2=\frac{1.46g}{2g/mol}=0.73mol[/tex]

and,

[tex]\text{Moles of }N_2=\frac{\text{Given mass }N_2}{\text{Molar mass }N_2}[/tex]

[tex]\text{Moles of }N_2=\frac{10.5g}{28g/mol}=0.375mol[/tex]

Now we have to calculate the limiting and excess reagent.

The balanced chemical equation is:

[tex]3H_2+N_2\rightarrow 2NH_3[/tex]

From the balanced reaction we conclude that

As, 3 mole of [tex]H_2[/tex] react with 1 mole of [tex]N_2[/tex]

So, 0.73 moles of [tex]H_2[/tex] react with [tex]\frac{0.73}{3}=0.243[/tex] moles of [tex]N_2[/tex]

From this we conclude that, [tex]N_2[/tex] is an excess reagent because the given moles are greater than the required moles and [tex]H_2[/tex] is a limiting reagent and it limits the formation of product.

Now we have to calculate the moles of [tex]NH_3[/tex]

From the reaction, we conclude that

As, 3 mole of [tex]H_2[/tex] react to give 2 mole of [tex]NH_3[/tex]

So, 0.73 mole of [tex]H_2[/tex] react to give [tex]\frac{2}{3}\times 0.73=0.487[/tex] mole of [tex]NH_3[/tex]

Now we have to calculate the mass of [tex]NH_3[/tex]

[tex]\text{ Mass of }NH_3=\text{ Moles of }NH_3\times \text{ Molar mass of }NH_3[/tex]

Molar mass of [tex]NH_3[/tex] = 17 g/mole

[tex]\text{ Mass of }NH_3=(0.487moles)\times (17g/mole)=8.28g[/tex]

Therefore, the theoretical yield in grams for this reaction under the given conditions is, 8.28 grams.

Answer:

252000j

Explanation:

Heat lost= heat gained

4200×2×3=heat lost

Energy =25200j

Answer: 2700 j

Explanation:

Q (energy) = m (mass) * t (change in temp) * c (specific heat capacity)

Plug in the values...

Q = 2(3)(0.45) (specific heat capacity of iron)

Q = 2.7 Kj

convert kilo joules to joules and you get 2700 j

Hope this helps :)

Answer:

I am gonna say d all of the above

Explanation:

I may be wrong sorry

Yes

The accuracy to which we can measure a value using a given instrument is dependent on the instrument's least count. The least count of this instrument is 0.1 grams, or a tenth of a gram. Therefore, we may measure to the tenth of a gram with confidence. We cannot measure to the hundredth of a gram however.

Answer:

A. They cycle elements through the biotic and abiotic components of an ecosystem.

Explanation:

Chemical elements such as nitrogen, carbon, phosphorus etc. moves between the living and non-living parts of an ecosystem in the biosphere. The cycle of these elements between these counterparts (abiotic and biotic) is referred to as the BIOGEOCHEMICAL CYCLE.

Firstly, the biotic components of an ecosystem refers to the living organisms such as plants, animals, microbes etc while the abiotic components are the non-living parts such as soil, water etc. Therefore, according to the description given in the options, option A describes what a BIOGEOCHEMICAL CYCLE best.

Answer:

A.The concentration of water is greater outside the cell than inside the cell.

Explanation:

The contractile vacuole of certain organisms functions to regulate water flow in and out of the cell. It does this by storing excess water that comes into the cell. In the case of this organism with a filled up contractile vacuole, it means water is flowing into the cell.

Naturally, water will flow into a living cell when an osmotic gradient i.e. difference in concemtration, has been created between intracellular and extracellular solutions. Osmosis involves movement of substances from a region of high water concentration to a region of low water concentration. This means that if water is flowing into the cell, which is stored by the contractile vacuole, the concentration of water must be greater outside the cell than inside.

Answer:

I think A) a phase change occurs

Answer:

a new gas is observed in the form of bubbles

Explanation:

just did it!

Answer:

The answer is Osmosis........

Answer:

osmosis

Explanation:

osmosis is a method of passive transport in cells. osmosis in passive transport cells is of water

Answer:

So as the reaction proceeds we lose energy as the reaction is exothermic due to the delta H being negative, this shows that heat flows from the system to its surroundings.

Explanation:

2H6O (l) + 3O2 (g) = 2CO2 (g) + 3H2O (g)

2CH3CH2OH(l) + 3O2(g) = 2CO2(g) + 3H2O(g) ΔH = -1234.8kJ/mol

I'm pretty sure this is what your equation is supposed to be, seems to be an error where you've pasted it and it's replaced the O's with )

So as the reaction proceeds we lose energy as the reaction is exothermic due to the delta H being negative, this shows that heat flows from the system to its surroundings.

Answer:

113.4g of N2

Explanation:

Step 1:

The balanced equation for the reaction.

N2 + 3H2 —> 2NH3

Step 2:

Determination of the mass of N2 and H2 that reacted from the balanced equation. This is illustrated below:

Molar mass of N2 = 2x14 = 28g/mol

Mass of N2 from the balanced equation = 1 x 28 = 28g

Molar mass of H2 = 2x1 = 2g/mol

Mass of H2 from the balanced equation = 3 x 2 = 6g

From the balanced equation above, 28g of N2 reacted with 6g of H2.

Step 3:

Determination of the mass N2 required to react with 24.3g of H2.

The mass of N2 required to react with 24.3g of H2 can be obtained as follow:

From the balanced equation above, 28g of N2 reacted with 6g of H2.

Therefore, Xg of N2 will react 24.3g of H2 i.e

Xg of N2 = (28 x 24.3)/6

Xg of N2 = 113.4g

Therefore, 113.4g of N2 is required to react completely with 24.3g of H2.

24.3g H2 × 1 mol H2/2.016g H2 × 1 mol N2/3 mol H2 × 28.014 g N2/1 mol N2 = 113g N2

Answer:

The answer is A

Explanation:

Because . . .

- A is correct because scientist make their statements by using their observations and tools to measure.

- B is incorrect people's opinions are not facts! Plus, opinions can be wrong.

- C is incorrect because that book can be outdated and not every answer is in a book.

- D is absolutely incorrect because guessing a "right" answer can be wrong. For example, if you were a scientist and you guessed a treatment for coronavirus, you will defiantly get fired because you don't have evidence or logic to back up your answer. In addition, if people used ur "treatment" the one you have guessed as the "right" answer, you can put people's lives in danger and they can possibly die. You will defiantly be responsible for it and be put into jail.

Answer:A

Explanation: