Answer:
601.8mL
Explanation:
First, we'll begin by obtaining an equation connecting volume and number of mole together. This is illustrated below:
From the ideal gas equation:
PV = nRT
Divide both side by P
V = nRT/P
Now divide both side by n
V/n = RT/P
Under the same conditions simply means temperature(T), pressure (P) and the gas constant (R) are all constant i.e
RT/P => constant
Therefore, the above equation can be written as:
V1/n1 = V2/n2
Now we can solve for the final volume otherwise known as the new volume as follow:
Data obtained from the question include:
n1 (initial mole) = 0.214 mol
V1 (initial volume) = 343.4 mL
n2 (final mole) = 0.375 mol
V2 (final volume) =?
Applying the the equation V1/n1 = V2/n2, the final volume is obtain as illustrated below:
V1/n1 = V2/n2
343.4/0.214 = V2/0.375
Cross multiply to express in linear form
0.214 x V2 = 343.4 x 0.375
Divide both side by 0.214
V2 = (343.4 x 0.375)/0.214
V2 = 601.8mL
Therefore, 0.375 mol of argon gas will occupy 601.8mL under the same condition.
Select all of the statements that are examples of technology in science. chemists using a computer program to analyze data from their experiments physicists using a water tank to observe the way waves interact with a model vehi biologists writing down observations of animal behavior physicists discussing the results of an experiment geologists using a seismograph to record vibrations moving through the Earth
Answer:
Explanation:
1. geologists using a seismograph to record vibrations moving through the Earth.
2. chemists using a computer program to analyze data from their experiments.
3. physicists using a water tank to observe the way waves interact with a model rehi.
Those three clearly describe the role of technology in science because all those researchers are using those technological equipment's for their scientific research to get an outcome (Result).
Chemists analyzing data, physicists observing wave behavior, and geologists recording seismic activity are all examples of technology being used in science.
Explanation:The statements that are examples of technology in science include:
Chemists using a computer program to analyze data from their experiments: This is an example of technology being used in chemistry to process and interpret experimental data.Physicists using a water tank to observe the way waves interact with a model vehicle: This is an example of technology being used in physics to observe and study wave behavior.Geologists using a seismograph to record vibrations moving through the Earth: This is an example of technology being used in geology to measure and record seismic activity.Learn more about Technology in Science here:https://brainly.com/question/12932006
#SPJ2
Select all of the following that are salts.
- NaNO3
- (NH4)2SO4
- H2SO4
- NH3
- NH4OH
- NaCl
- NH4Cl
Answer:
NaNO3
NaCI
(NH4)2SO4
NH4Cl
Explanation:
Odyssey ware
Calculate OH- given .010 M h+
Answer:
(OH-)=1x10^-12 M
Explanation:
Both pH and pOH have a relationship to belonging to the same aqueous solution: the expression of the Kwater (ionic product of the water Kw) is used:
(H3O+) x (OH-) = 1x10^-14
(0,010) x (OH-)= 1x10^-14
(OH-)=1x10^-14/(0,010)
(OH-)=1x10^-12 M
A metal block has a mass of 122 grams and measures 2cm x 2cm x 4cm. What is the density of the block?
Answer:
7.625g/cm³
Explanation:
Density = mass/volume
Volume of the block=2cm×2cm×4cm=16cm³
Mass of the block=122g
Density=122/16
=7.625
Therefore, the density of the block is 7.625g/cm³
If 6.0g of carbon is heated in air, the mass of the product obtained could be either 22.0g or 14.0g depending on the amount of air present. Show that this verifies the law of multiple proportions.
please explain
Answer:
See the demonstration belowExplanation:
The law of multiple proportions states that, when two elements can react with each other to form two or more different compounds, the weights of one element that react with a fixed weight of the other are in a ratio of small whole numbers.
1. If the mass of product obtained were 22.0g
Then, the mass of the oxygen atoms in the product would be:
22.0g - 6.0g = 16.0gThe ratio of the weight of oxygen to the weight of carbon is 16.0 g to 6.0 g,
16.0g : 6.0g = 8 : 3.2. If the mass of product obtained were 14.0g.
Mass of oxygen = 14.0g - 6.0g = 8.0 gRatio oxgyen to carbon = 8.0g / 6.0g = 4 : 33. Conclusion
Take a fixed amount of carbon equal to 3 grams.
Then, the amount of oxygen for the first compound would be 8 grams and the amount of oxygen for the second compound would be 4 grams.
That means that the ratio is 8 : 4 = 2.
Which is saying that, for the two compounds of carbon and oxygen, the weights of oxygen that reacts with a fixed weight of carbon are in a ratio of small whole numbers, in accordance to the law of multiple proportions.
Mrs. Jacobson is pushing a fridge to the right with a force of 100 N. The force pushing it
to the left is 15 N. What is the net (leftover) force on the fridge?
85 N to the right
85 N to the left
115 N to the right
115 N to the left
Answer:
A
Explanation:
Let's illustrate this; see the attachment.
We see that Mrs. Jacobson is pushing to the right with a force of 100 N and there is another opposite force pushing with a force of 15 N. Since these are in opposite directions, we can say that the force opposite to Mrs. Jacobson is pushing the fridge -15 N to the right (instead of 15 N to the left).
The net force would then be:
100 N + (-15 N) = 85 N to the right
The answer is A.
Answer:
85 N to the right
Explanation:
Convention: rightwards positive
Force applied by Mrs. Jacobson:
+100
Force applied by the fridge:
-15
Net force
+100 - 15
+85
a gas has a volume of 350 cubic centimeters at 740 mmHg. how many cubic centimeters will the gas occupy at a pressure of 900 mmHg if the temperature remains constant?
Answer: 287.8 cm3
Explanation:
Given that:
Initial volume of gas V1 = 350 cm3
Initial pressure of gas P1 = 740 mmHg
New volume V2 = ?
New pressure P2 = 900 mmHg
Since, pressure and volume are involved while temperature is constant, apply the formula for Boyle's law
P1V1 = P2V2
740 mmHg x 350 cm3 = 900mmHg x V2
V2 = (740 mmHg x 350 cm3) /900mmHg
V2 = 259000 mmHg cm3 / 900mmHg
V2 = 287.8 cm3
Thus, the gas will occupy 287.8 cubic centimeters at the new pressure.
What is the pH of a 2.5x 10^-6M Solution of HCI?
Answer:
5.6
Explanation:
since HCl is a strong acid we know that it completely dissasociates into H+ and Cl-
We can just treat the HCl as the H+ concentration and take the -log
-log(2.5E-6) = 5.6
How much heat is needed to raise the temperature of 55.0 g sample of water by 65.0 oC.
The specific heat of water is 4.18 J/g oC. (Q = mxcx AT)
PLEASE HELP
Final answer:
To raise the temperature of a 55.0 g sample of water by 65.0°C, 14943 joules of heat energy is required, calculated using the specific heat capacity of water and the formula for heat energy.
Explanation:
The student asks about the quantity of heat energy needed to raise the temperature of a given sample of water. To calculate this, we will use the formula Q = m × c × ΔT, where 'Q' is the heat energy in joules (J), 'm' is the mass of the water in grams (g), 'c' is the specific heat capacity (4.18 J/g°C for water), and 'ΔT' is the change in temperature (°C).
In this scenario, the mass of water is 55.0 g, and we want to heat it by 65.0 °C. Therefore, we calculate the heat energy required as follows:
Q = 55.0 g × 4.18 J/g°C × 65.0 °C
Q = 55.0 × 4.18 × 65.0
Q = 14943 J
So, 14943 joules of heat energy is required to raise the temperature of a 55.0 g sample of water by 65.0°C.
on a timer!
The chart shows the amount of solute that fully dissolved when added to 500 ml of water.
Which ranks the solutions in order of greatest to least solubility?
X → Y → Z
Y → X → Z
Z → X → Y
Y → Z → X
Answer:
B
Explanation:
Answer:
β the answer is β
Explanation:
Which of the following water solutions would likely have the highest boiling point?
Question 6 options:
1.8 M
0.20 M
0.75 M
1 M
Answer:
1m
Explanation:
Write the chemical reactions for a weak acid and a strong acid.
The dissociation reaction of weak acid is
[tex]HA_{aq} +H_{2}O_{l} \rightleftharpoons H_{3}O^{+} +A^{-} _{aq}[/tex]
For strong acid dissociation reaction is given by
[tex]HA_{aq} +H_{2} O_{l}\rightarrow H_{3}O^{+}+A^{-} _{aq}[/tex]
What is dissociation reaction?Dissociation is a reaction in which acid release its hydronium ion in water. Dissociation of acid depends on the kind of solvent that are there with acids.
Strong acid dissociates at is fullest, means all the hydronium ions releases from acid so it is irreversible reaction, rate of dissociation of acid is very high. Hydrochloric acid is example of strong acid.
Whereas in case of weak acid, It does not dissociate at its fullest level, its dissociation is poor. The rate of dessociation of acid is very low. Acetic acid is an example of weak acid. Dissociationin weak acid is a reversible process.
Thus dessociation of weak acid is poor while in case of strong acid it is very high.
To learn more about dessociation reaction,here:
https://brainly.com/question/15220646
#SPJ5
A weak acid partially dissociates in water, for example, CH₃COOH forms CH₃COO⁻ and H⁺. A strong acid fully dissociates, like HCl into H⁺ and Cl⁻. HCl is a stronger acid than HF, and in a neutralization reaction, H⁺ reacts with OH⁻ to form water.
Chemical reactions involving acids can be represented by their ionization in water. A weak acid like acetic acid (CH₃COOH ) partially dissociates in water to form CH3COO⁻ and H⁺ ions:
CH₃COOH(aq) + H₂O(l) ↔ CH₃COO⁻(aq) + H⁺(aq)
A strong acid such as hydrochloric acid (HCl) fully dissociates in water to give H⁺ and Cl⁻ ions:
HCl(aq) → H⁺(aq) + Cl⁻(aq)
Answering the specific question on which of the two acids HCl(aq) or HF(aq) is stronger: HCl(aq) is the stronger acid since it completely dissociates in solution, whereas HF(aq) partially dissociates, making it a weak acid.
For the neutralization of a strong acid with a base, the net ionic equation generally represents the reaction between hydrogen ions and hydroxide ions to form water. An example of such a reaction is:
H⁺(aq) + OH⁻(aq) → H₂O(l)
Radium decays to form radon. Which equation correctly describes this decay?
Answer:
D
Explanation:
Answer:
A Alpha
Explanation:
What causes the trade winds?
Answer: Trade winds are caused by the strong warming and evaporation within the atmosphere around the equator. (1) Around the equator, the warm air rises rapidly, carrying a lot of moisture.
Answer:
The Coriolis Effect.
Explanation:
combination with an area of high pressure, causes the prevailing winds—the trade winds—to move from east to west on both sides of the equator across this 60-degree "belt.
C(s)+ 1 /2 O 2 (g) CO(g) CO(g)+ 1 /2 O 2 (g) CO 2 (g) How will oxygen appear in the final chemical equation?
Answer : The oxygen will appears in the final chemical equation as a reactant.
Explanation :
The given chemical reactions are:
(1) [tex]C(s)+\frac{1}{2}O_2(g)\rightarrow CO(g)[/tex]
(2) [tex]CO(g)+\frac{1}{2}O_2(g)\rightarrow CO_2(g)[/tex]
Now we are adding reaction 1 and reaction 2, we get the final chemical equation.
The final chemical equation is:
[tex]C(s)+O_2(g)\rightarrow CO_2(g)[/tex]
Thus, the oxygen will appears in the final chemical equation as a reactant.
Answer:
The oxygen will appears in the final chemical equation as a reactant.
Explanation:
got a 100% on the unit test
A company uses a substance that is Solid under normal conditions this substance will be used in extreme conditions which could make this substance molecules move faster and cause a phase change how would this phase change occur , and how would the molecules of the substance be affected under these extreme conditions
The shift often happens when heat is applied or removed at a specific temperature, also referred to as the substance's melting or boiling point. The temperature at which a substance transforms from a solid into a liquid is known as the melting point.
What is temperature ?The physical concept of temperature indicates in numerical form how hot or cold something is. A thermometer is used to determine temperature. Thermometers are calibrated using a variety of temperature scales, which historically defined distinct reference points and thermometric substances.
When a substance immediately transitions from the solid to gas state, it is said to sublimate. Deposition is the opposite of sublimation, occurring when a substance changes from a gaseous state to a solid state.
For instance, you have undoubtedly seen the simple processes of forming ice, melting ice, and boiling water to cause freezing, melting, and vaporization. Cold beverage containers frequently develop condensation on their exteriors. When this happens, the liquid on the container's surface is created straight from the humid air.
Thus, The temperature at which a substance transforms from a solid into a liquid is known as the melting point.
To learn more about the temperature, follow the link;
https://brainly.com/question/11464844
#SPJ5
How many atoms are in 3.75 mol of calcium?
Answer:
Number of atoms = 22.58×1023
Explanation:
Hydrogen atoms absorb energy so that the electrons are excited to n=4. Calculate the wavelength, in
nm, of the photon emitted when the electron relaxes to n=2.
487nm
O 456nm
4.56 x 10 nm
4.87 x 107nm
Answer:
the wavelength, in nm, of the photon is 487.5 nm
Explanation:
Given:
n = 4 (excited)
n = 2 (relaxes)
Question: Calculate the wavelength, in nm, λ = ?
First, it is important to calculate the energy of the electron when it excited and then when it relaxes.
[tex]E_{1} =\frac{-13.6}{n^{2} } =\frac{-13.6}{4^{2} } =-0.85eV[/tex] (excited)
[tex]E_{2} =\frac{-13.6}{2^{2} } =-3.4eV[/tex] (relaxes)
The change of energy
ΔE = E₁ - E₂=-0.85 - (-3.4) = 2.55 eV = 4.08x10⁻¹⁹J
For a photon, the wavelength emitted
[tex]\lambda =\frac{hc}{delta(E)}[/tex]
Here
h = Planck's constant = 6.63x10⁻³⁴J s
c = speed of light = 3x10⁸m/s
Substituting values:
[tex]\lambda =\frac{6.63x10^{-34}*3x10^{8} }{4.08x10^{-19} } =4.875x10^{-7} m=487.5nm[/tex]
How many mol of sodium hydroxide are required to make 1.35 L of 2.50 mL solution?
Final answer:
To make a 1.35 L solution, 0.189 mol of sodium hydroxide (NaOH) is required.
Explanation:
To find the number of moles of sodium hydroxide (NaOH) required to make a 1.35 L solution, we first need to determine the concentration of the solution in mol · dm-3. Given that 3.5 g of NaOH is dissolved in 2.5 dm3 of water, we can calculate the concentration using the formula:
Concentration (mol · dm-3) = moles of solute / volume of solution (dm3)
Concentration = (3.5 g / 39.997 g/mol) / 2.5 dm3 = 0.14 mol · dm-3
Now, to find the number of moles of NaOH required for a 1.35 L solution, we can use the formula:
Moles of solute = concentration · volume (L)
Moles of NaOH = 0.14 mol · dm-3 × 1.35 L = 0.189 mol
Given the equation: butanoic acid + 1-pentanol catalyst water + X
To which class of organic compounds does product X belong?
The product X belongs to ester class of organic compounds.
What is catalyst in chemical reaction ?Catalyst is a substance or material that speeds up a chemical reaction.
What is Ester group ?The chemical formula of ester group is RCOOR¹. Esters are formed when the alcohol and carboxylic acid reacts. Here butanoic acid is carboxylic acid and 1-pentanol is alcohol group.
The given equation is:
Butanoic Acid + 1-Pentanol [tex]\overset{H^+}\rightarrow[/tex] X + water
CH₃-CH₂-CH₂-COOH + CH₃-CH₂-CH₂-CH₂-CH₂OH [tex]\overset{H^+}\rightarrow[/tex] CH₃-CH₂-CH₂-COO CH₂-CH₂-CH₂-CH₂-CH₃ + water
Here X belongs to ester group.
Thus, from above conclusion we can say that the product X belongs to ester class of organic compounds.
Learn more about the Ester group here: https://brainly.com/question/9165411
#SPJ2
Consider the redox reaction below.
Upper M g (s) plus Pper f e superscript 2 plus (a q) right arrow upper M g superscript 2 plus (a q) plus upper F e (s).
Which equation is a half reaction that describes the reduction that is taking place?
Upper F e superscript 2 plus (a q) plus 2 e superscript minus right arrow upper F e (s).
Upper M g (s) right arrow upper M g superscript 2 plus (a q) plus 2 e superscript minus.
Upper Fe superscript 2 plus (a q) right arrow upper F e (s) plus 2 e superscript minus.
Upper M g (s) plus 2 e superscript minus right arrow upper Mg superscript 2 plus (a q).
Answer:
See explanation below
Explanation:
To answer this better, let's write the overall equation:
Mg(s) + Fe²⁺(aq) -----------> Mg²⁺(aq) + Fe(s)
Now the question shows us options of which equation is the half reaction that describes reduction. To do this, we need to know what is happening here, and what a reduction means here.
A reduction in a reaction takes place when an atom or compound gains electrons. This can be easily identified in this reaction because when an atom has a higher positive number, means that it's losing electron, and if it has a lower positive number and even negative numbers, means that is gaining the electrons.
In other words, if you have a number line, and put the 0 in the center, any movement that goes from 1 position to the right of the line, means that it's losing electrons (oxidizing) and if it goes to the left, it's gaining electrons (Reduction).
With this explained, let's write the half reactions taking place:
Mg(s) -----------> Mg²⁺
Fe²⁺ -----------> Fe(s)
When an atom it's in solid state, the oxidation number of the atom it's always zero, therefore, in the case of Mg, it goes from 0 to 2+, and Fe goes from 2+ to 0. According to the explanation above, if we go to the left we are reducting and if we go to the right, we are oxidizing. Therefore, as Fe goes from 2+ to 0, this means that is gaining 2 electrons, and it's reducting while Mg, it's oxidizing and losing electrons.
The half reactions then:
Mg(s) -----------> Mg²⁺ + 2e⁻ (Oxidizing)
Fe²⁺ + 2e⁻-----------> Fe(s) (Reducting)
In this case, it would be the option 1.
Answer:
It's A
Explanation:
Assuming all the substances below have the same mass, which substance
below requires the least energy to raise its temperature by 7°C? Use the table
to help you answer the question.
Substance
Specific Heat
J/(kg )
900
Aluminum
Gold
Water
4.184
Wood
O
A. Gold
O
B. Aluminum
O C. Wood
O
D. Water
Answer:
Gold.
Explanation:
The specific heat is the measure to determine which material needs a lesser amount of energy to rise its temperature. Specific heats are described below:
Aluminium: [tex]903\,\frac{J}{kg\cdot ^{\circ}C}[/tex]
Gold : [tex]129\,\frac{J}{kg\cdot ^{\circ}C}[/tex]
Water: [tex]4184\,\frac{J}{kg\cdot ^{\circ}C}[/tex]
Wood: [tex]1300\,\frac{J}{kg\cdot ^{\circ}C}[/tex]
Gold reports the lowest specific heat and, hence, requires the least energy to raise its temperature 7°C.
At what temperature Kelvin would
4.00 mol H2 in a 100 L container
exert a pressure of 1.00 atm?
Answer:
The temperature would be 304, 87 K
Explanation:
We use the formula PV= nRT:
T= PV/nR = 1,00 atm x 100L /4,00 mol x 0,082 l atm/K mol=304, 87 K
The temperature would be 304, 87 K
can two isotopes of the same element have different numbers of protons?
Hey there!
Your answer is no.
The difference between isotopes is the number of neutrons, not the number of protons.
For example, we have carbon-12 and carbon-14, two different isotopes of carbon. One has 6 protons and 6 neutrons, while one has 6 protons and 8 neutrons. They have the same amount of protons.
If you change the number of protons, then you have a different element. Isotopes are the same element.
Hope this helps!
What is the volume of the air in a balloon that occupies 8.7 L at 50.0°C if the temperature is lowered to 25.0°C?
Answer:
8.03L
Explanation:
Given parameters:
Initial volume, V₁ = 8.7L
Initial temperature T₁ = 50°C , in Kelvin gives 50+273 = 323K
Final temperature T₂ = 25°C, in Kelvin gives 25 + 273 = 298K
Unknown:
Final volume V₂ = ?
Solution:
Since we are dealing with volume and temperature relationships under constant pressure, we simply apply the Charles's law.
Charles's law states that "the volume of a given mass of gas is directly proportional to the temperature provided the pressure remains constant".
Mathematically, we have;
[tex]\frac{V_{1} }{T_{1} } = \frac{V_{2} }{T_{2} }[/tex]
where V andV T are volume and temperature, 1 and 2 are initial and final states.
Input the parameters and solve for V₂;
[tex]\frac{8.7}{323} = \frac{V_{2} }{298}[/tex]
V₂ = 8.03L
How many grams of O2 are needed to produce 0.400 mole Fe2O3 in the following reaction?
4 Fe(s) + 3 028 2 Fe2O3(s)
Answer
7.2 g of Oxygen are needed to produce 0.400 mole Fe₂O₃ in the following reaction
Explanation:
4 Fe(s) + 3O₂= 2 Fe₂O₃(s)
4 moles of Fe reacts with 3 moles of oxygen to give 2 moles of Fe₂O₃
to get the grams of oxygen needed to produce 0.400 mole Fe₂O₃ in the following reaction
we first get the moles then convert it to grams
3 moles of oxygen are needed to give 2 moles of Fe₂O₃ in the equation thus we have 3:2
let the represent the moles of oxygen that will be intended for 0.400 mole Fe₂O₃ in the following reaction
x:0.4
3:2=x:0.4
3/2 = x/0.4
cross multiply
3x0.4 = 2x
1.2 = 2x
x= 1.2/2 = 0.6
moles is 0.6
1 mole of Oxygen is 12g of Oxygen
0.6 mole of oxygen will give = 0.6 x12= 7.2 g of Oxygen
7.2 g of Oxygen are needed to produce 0.400 mole Fe₂O₃ in the following reaction
To produce 0.400 moles of Fe₂O₃, 95.8 g of O₂ are needed.
Let's consider the following balanced equation.
4 Fe(s) + 3 O₂(g) ⇒ 2 Fe₂O₃(s)
We can calculate the grams of O₂ needed to produce 0.400 moles of Fe₂O₃ considering the following relationships.
The molar mass of Fe₂O₃ is 159.69 g/mol.The molar ratio of Fe₂O₃ to O₂ is 2:3.[tex]0.400molFe_2O_3 \times \frac{159.69gFe_2O_3}{1molFe_2O_3} \times \frac{3molO_2}{2molFe_2O_3} = 95.8 gO_2[/tex]
To produce 0.400 moles of Fe₂O₃, 95.8 g of O₂ are needed.
Learn more: https://brainly.com/question/9743981
How many grams of O₂ are needed to produce 0.400 mole Fe₂O₃ in the following reaction?
4 Fe(s) + 3 O₂(g) ⇒ 2 Fe₂O₃(s)
what is the full form of alcl3
Answer:
Aluminum Chloride
Explanation:
Pick one option:
The ________ ion has a noble gas electron configuration.
Li2+
Li2-
Li
Li+
Li-
Answer:
Li⁺
Explanation:
Li⁺ ions has a noble gas electron configuration because it resembles that of He.
To have a noble configuration, electrons in the outermost shell must completely fill their respective orbitals.
Li⁺ is an ion that has lost one electron from the usual number of 3 thereby remaining 2 electrons.
The electronic configuration is given as;
Li⁺ 1s²
The S orbital can hold a maximum number of just two electrons.
Helium atom has two electrons with electronic configuration of 1s²
Therefore Li⁺ = 1s² = He
The Li+ ion has a noble gas electron configuration, which mirrors the electron configuration of helium (He) by having two electrons in the 1s subshell after losing one valence electron.
Explanation:The Li+ ion has a noble gas electron configuration. Lithium (Li) has an atomic number of 3, which corresponds to three electrons in a neutral atom. These three electrons are arranged in the 1s subshell (two electrons) and the 2s subshell (one electron), giving lithium an electron configuration of 1s²2s¹. When lithium loses its one valence electron, it forms a Li+ cation with a configuration of 1s², which mirrors the electron configuration of the noble gas helium (He). Since lithium is an alkali metal in Group 1A of the periodic table, it tends to form a 1+ charge when it becomes an ion, which is indicated by the noble gas electron configuration it achieves as Li+.
Dr. von Waldner conducts research on depression. His hypothesis is that depression results from maladaptive thought patterns. From which perspective is von Waldner working?
a. Humanistic
b. Psychodynamic
c. Cognitive
d. Physiological
Answer: The answer is C
Explanation:
400ml of 2.5M can be deluded to make how many of 2.0 HCI
Answer:
The new volumen of the solution is 500 ml.
Explanation:
A dilution consists of the decrease of concentration of a substance in a solution (the higher the volume of the solvent, the lower the concentration).
We use the formula for dilutions:
C1 x V1 = C2 x V2
V2= (C1xV1)/C2
V2= (400 ml x 2,5 M)/2,0M
V2= 500 ml