A gas has a pressure of 0.0370 atm at 50.0°C. What is the pressure at 0.00°C?

Answer:

23.6 moles

Explanation:

From the question given above, the following data were obtained:

Mass of air = 3.6 Kg

Mass percentage of O₂ = 21%

Number of mole of O₂ =?

Next, we shall convert 3.6 Kg of air to grams (g). This can be obtained as follow:

1 kg = 1000 g

Therefore,

3.6 Kg = 3.6 Kg × 1000 / 1 kg

3.6 Kg = 3600 g

Next, we shall determine the mass of O₂ in the air. This can be obtained as follow:

Mass of air = 3600 g

Mass percentage of O₂ = 21%

Mass of O₂ =?

Mass of O₂ = 21% × 3600

Mass of O₂ = 21/100 × 3600

Mass of O₂ = 756 g

Finally, we shall determine the number of mole of O₂ in the sample of air. This can be obtained as follow:

Mass of O₂ = 756 g

Molar mass of O₂ = 2 × 16 = 32 g/mol

Number of mole of O₂ =?

Mole = mass /Molar mass

Number of mole of O₂ = 756 / 32

Number of mole of O₂ = 23.6 moles

Thus, the number of mole of O₂ in the

sample of air is 23.6 moles

Explanation:

number of moles =mass /relative molecular mass

n=10g/mr(FeSO4)

N=10/(56+32+16×4)

N=10/152

N=0,066 moles

Answer:

What is the functional groups of CH3CH2CH(OH)CH2C(CH3)2Br?

Answer:

depends on what molecule you are looking for

Explanation:

In one mole of stuff (atoms, molecules, eggses), there are NA individual items of that stuff. So, there are 4.5 × NA BCl3 molecules; i.e. 4.5 × 6.022×1023 ≅ 27×1023 individual molecules of BCl3

Answer: [tex]K_a[/tex] for the acid is [tex]3.34\times 10^{-4}[/tex]

Explanation:

[tex]HC_9H_7O_4\rightarrow H^+C_9H_7O_4^-[/tex]

 cM              0             0

[tex]c-c\alpha[/tex]        [tex]c\alpha[/tex]          [tex]c\alpha[/tex]  

Give c = 0.328 M and [tex]pH=1.987[/tex]

[tex]1.987=-log[H^+][/tex]

[tex][H^+]=0.0103[/tex]

[tex][H^+]=c\times \alpha[/tex]

[tex]0.0103=0.328\times \alpha[/tex]

[tex]\alpha=0.0314[/tex]

So dissociation constant will be:

[tex]K_a=\frac{(c\alpha)^{2}}{c-c\alpha}[/tex]

Putting in the values we get:

[tex]K_a=\frac{(0.328\times 0.0314)^2}{(0.328-0.328\times 0.0314)}[/tex]

[tex]K_a=3.34\times 10^{-4}[/tex]

Answer:

violet

Explanation:

just violet

oh and you spelled "COLER" wrong, its color or colour if you live somewhere else

Answer:

D H2PO4– + HPO42–

Explanation:

The acid dissociation constant for [tex]\mathbf{H_3PO_4 , H_2PO^{-}_4 , HPO_4^{2-}}[/tex] are [tex]\mathbf{7\times 10^{-3}, \ \ 8\times 10^{-8} ,\ \ 5\times 10^{-13}}[/tex] respectively.

[tex]\mathbf{pka (H_3PO_4) = -log (7\times 10^{-3} )=2.2}[/tex]

[tex]\mathbf{pka (H_2PO_4^-) = -log (8\times 10^{-8} )=7.1}[/tex]

[tex]\mathbf{pka (HPO_4^{2-}) = -log (5\times 10^{-13} )=12.3}[/tex]

The reason while option D is the best answer is that, the value of pKa for both

[tex]\mathbf{H_2PO^{-}_4 ,\ \& \ HPO_4^{2-}}[/tex] lies on either side of the desired pH of the buffer. This implies that one is slightly over and the other is slightly under.

Using Henderson-Hasselbach equation:

[tex]\mathbf{pH = pKa + log \Big( \dfrac{HPO_4^{2-}}{H_2PO_4^-} \Big)}[/tex]

The compounds that are used for the formulation of the pH 9 buffer are [tex]\rm H_2PO_4^-\;and\;HPO_4^+[/tex]. Thus, option D is correct.

The buffers are the solutions of acids and base of appropriate pH, that are able to limit the change in pH in the reaction mixture.

The buffer pH is adjusted with the compounds that has been able to add base or acid to the solution.

For the formulation of buffer of specific pH, the acid and base solutions are required.

The compounds that are used for the formulation of the pH 9 buffer are [tex]\rm H_2PO_4^-\;and\;HPO_4^+[/tex], as they are able to provide acid and base to the solution.

Thus, option D is correct.

Learn more about buffers, here:

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Answer:

See explanation

Explanation:

Rf value is known as retention factor.The retention factor of a particular material is the ratio of the distance the spot moved above the origin to the distance the solvent front moved above the origin(Harper College).

TLC is carried is out in a closed container and the interior is saturated with the solvent vapor in order to have a maximum resolution between components this prevents solvent from evaporating from the system.

Peradventure the solvent for the separation is partly or wholly  lost due to an open container, the Rf value would be lower than the expected value.

Answer:

See answer below

Explanation:

In this case, let's draw the butane molecule:

CH₃ - CH₂ - CH₂ - CH₃

According to what the exercise states, we removed an atom of hydrogen from the frist carbon. This could be any of the terminals. I'll grab the first from left to right.

CH₂⁺ - CH₂ - CH₂ - CH₃

When this happens, the atom of carbon is lacking one space and it forms a carbocation.

Followed this step, an hydroxile group replace the atom of hydrogen. The hydroxile is the OH, and when we have an alkane with an OH group in the molecule, we are actually converting this molecule into an alcohol, therefore the molecule formed is:

Hope this helps

Answer:

im not doing your whole homework. but ill give you  one cent ;>, whats ur paypal

Explanation:

Answer:

[tex]Q=-15.3kJ[/tex]

Explanation:

Hello!

In this case, since the enthalpy of vaporization is the contrary of the enthalpy of condensation, we have:

[tex]\Delta _{cond}H=-\Delta _{vap}H=-38.0kJ/mol[/tex]

Now, we convert the grams of CH3OH to moles:

[tex]n=12.9g*\frac{1mol}{32.05g}=0.402mol[/tex]

Thus, we compute the energy as shown below:

[tex]Q=n*\Delta _{cond}H=0.402mol*-38.0\frac{kJ}{mol}\\\\Q=-15.3kJ[/tex]

Which means 15.3 kJ of energy must be back down from the system.

Best regards!

Enthalpy is the measure of the energy that is not available to work. 15.27 kJ of energy is needed to condence 12.9 g of methenol.

Enthalpy:

It is the measure of the energy that is not available to work. It is denoted by [tex]\bold{ \Delta H}[/tex].

The energy of a system can be calculated by the formula,

[tex]\bold{Q = n \times \Delta H}[/tex]

Where,

Q - energy( in kJ)

n - Number of moles

[tex]\bold{ \Delta H}[/tex] - enthalpy

Given here,

[tex]\bold{CH_3OH = 12.9 g}[/tex]

[tex]\bold{\Delta Hvap = 38.1 kJ/mol}[/tex]

molar mass of the [tex]\bold{CH_3OH}[/tex] -

The number of moles of [tex]\bold{CH_3OH}[/tex]

[tex]\bold{n = \frac{w}{m}}\\\\\bold{n = \frac{12.9}{32.03}} \\\\\bold{n = 0.402}[/tex]

Put the values in the formula,

[tex]\bold{Q = 0.402\times 38.0}\\\\\bold{Q =15.27 }[/tex]

Therefore, the 15.27 kJ of energy is needed to condense 12.9 g of methenol.

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Answer: 0.0450 moles of [tex]CaCl_2[/tex]

Explanation:

According to avogadro's law, 1 mole of every substance weighs equal to its molecular mass and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.

To calculate the moles, we use the equation:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}[/tex]

[tex]\text{Number of moles of} CaCl_2=\frac{5.00g}{110.98g/mol}=0.0450moles[/tex]

Thus there are 0.0450 moles of [tex]CaCl_2[/tex]

Answer:

True.

Explanation:

When the number of molecules, atoms or ions of any element is in the hundreds of millions, we can safely speak of concentrations and analyze a standard behavior, and can even specify the different dilutions used, if there are dilutions. This allows analyzes to be clearly understood by any individual. However, it is not possible to do this if the number of molecules, atoms and ions is very small.

Answer:

3 hours

Explanation:

To know the the correct answer to the question given above, it is important we know the definition of half-life.

The half-life of a substance is simply defined as the time taken for half the substance to decay.

Considering the diagram given above, the initial mass of the substance is 100 g.

Half of the initial mass = 100 / 2 = 50 g

Now, we shall determine the time from the graph taken to get to 50 g.

Considering the diagram given above, the time taken to get to 50 g is 3 hours.

Therefore, the half-life of the material is 3 hours.

Answer: 90.04°C

Explanation: Calorimeter is a device measures the amount of heat of a chemical or physical process. An ideal calorimeter is one that is well-insulated, i.e., prevent the transfer  of heat between the calorimeter and its surroundings. So, the net heat change inside the calorimeter is zero:

[tex]q_{1}+q_{2}=0[/tex]

Rearraging, it can be written as

[tex]q_{1}=-q_{2}[/tex]

showing that the heat gained by Substance 1 is equal to the energy lost by Substance 2.

In our case, water is gaining heat, because its temperature has risen and so, brass is losing energy:

[tex]q_{water}=-q_{brass}[/tex]

Calculating:

[tex]m_{w}.c_{w}.\Delta T=-[m_{b}.c_{b}.\Delta T][/tex]

[tex]100.4.18.(18.4-15)=-[52.9.0.375.(18.4-T)][/tex]

Note: final temperature is the same as the substances are in thermal equilibrium.

Solving:

418(3.4)= - 365.01 + 19.8375T

19.8375T = 1786.21

T = 90.04

The initial temperature for the sample of brass was 90.04°.

Answer:

3iron + chlorine=iron3 chloride

nitrogen +3hydrogen

Answer:

a) Iron + chlorine → Iron (iii) chloride

3fe+cl__fe3cl

b) Nitrogen + hydrogen → Ammonia

2N+3h2------2NH3

c) Phosphoric acid + sodium carbonate → sodium phosphate + water + carbon dioxide

2H3PO3+3Na2CO3-----2Na3PO4+3H2O+3CO2

d) Nitrogen dioxide + water + oxygen → Nitric acid

NO2+H2O+O2--NOH

sorry if mistake

Answer:

The electricity that flows to our homes is generated in the power station from here it flows through large transmission line which carry it to substations finally distribution carry electricity from substations to homes schools etc

Answer:

It released hydroxide ions (OH ¯).

Explanation:

A PH of 8.3 indicates that the solution has become a basic solution.

Now, for us to have a basic solution from the addition of an alka-seltzer to Koolaid, it means the Alka-seltzer released plenty of hydroxide ons (OH¯) to the solution.

Answer:

Volume = 19.68 ml

Explanation:

The equation of the reaction is given as;

HNO3 + KOH ---> KNO3 + H2O

1 mol of HNO3 reacts 1 mol of KOH

Converting 0.276 g of KOH to mol;

Number of moles = Mass / Molar mass

Number of moles = 0.276g / 56.1056 g/mol

Number of moles = 0.00492

Since the mole relationship is 1 = 1;

This means 0.00492 mol of HNO3 reacts with 0.00492 mol of KOH

The relationship between molarity and volume id given as;

Molarity = Number of moles / Volume

Volume = Number of moles / Molarity = 0.00492 mol / 0.250 M

Volume = 0.01968 L

Volume = 19.68 ml

Answer:

Crest is the highest point of a wave

When hydrogen and oxygen combine, they form water or hydrogen peroxide, and energy is released in the process.

Oxygen and hydrogen are the chemical elements of the periodic table, and they both are gas. Oxygen is the most important gas, which is needed for breathing. It is present at 21% in the atmosphere.

Hydrogen is another gas present in nature. It is the lightest gas, and it has diatomic molecules. It remains gas at normal pressure and temperature, but it becomes liquid at low temperature.

The oxygen and hydrogen readily react and for water, and hydrogen peroxide, the process of reaction of hydrogen and oxygen releases an amount of energy.

Hence, Energy is released during the creation of water or hydrogen peroxide when hydrogen and oxygen mix.

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Answer:

donate unused food to food banks

Explanation:

Becuse food banks processes food to make very fine particles which is mixed with soil and can be given to the plants

Answer: A chemical compound can be described as substance composed of atoms from more than one element held together by chemical bonds in a fixed stoichiometric proportion. A compound has different physical and chemical properties from its constituent elements.

For example : compound water is made up of H and O bonded together and it has different properties from O and H.

Thus, among the given options, the one coreectly describing a compound is

a) The atoms are bonded together, and the compound has different physical and chemical properties than the individual elements.

Answer: 190.9K

Explanation:

5.6(14) = 5(.0821)T  or  (5.6*14)/(5(.0821))

78.4 = 0.4105T

190.9K = T

Answer: hope this helps

Explanation: I’m not sure but after some research here’s what I gathered The molecule has 3 calcium atoms, 2 phosphate atoms and 8 O atoms in it also rate this and pls thank me follow and as as many questions as you need.

Answer:

0.1529mol

Explanation:

Number of mole = x mol

Mass = 52.3g

Molar Mass of Sucrose

(C = 12, H = 1, O = 16)

C12H22O11

(12×12)+(1×22)+(16×11)

144 + 22 + 176

342g/mol

Number of Mole = Mass given/Molar mass

Number of mole = 52.3/342

Number of mole = 0.1529mol

Answer:

See explanation below

Explanation:

Let's answer this by parts.

a) As the reaction is naturally exothermic (Exerts heat), increasing temperature means that the reaction will move forward the direction where its absorbing heat

, so the equilibrium will be favored to the reactant side.

b) In this case, the addition of CO, which is a reactant will favor the reaction to the product side. This is because putting more quantity in the reactants will cause that the equilibrium constant K, increase it's innitial value, and this favors the product side.

c) In this case, it happens something similar to case b. This will cause that the reaction will have to work to cover the loss of methanol, therefore, equilibrium will move to the product side too.

d) In this case, we are adding another substance that reacts with CO, so it means that the other reactant is being removed, therefore, the reaction will work to cover this loss but also to cover the adding of the new substance, causing that the K decrease it's value, so equilibrium will be favored to the reactants side.

Hope this helps

Answer:

0.01 M

Explanation:

NaOH (sodium hydroxide) is a strong base, so it is completely dissociated into ions in aqueous solution:

NaOH ⇄ Na⁺ + OH⁻

So, we have OH⁻ ions in solution.

From the problem, we have the pH value. The pH is calculated as:

pH = -log [H⁺]

As NaOH is a base, we can also calculate the pOH:

pOH = -log [OH⁻]

Thus. we can use the relation between pH and pOH to calculate the pOH and then use it to calculate [OH⁻]:

pH + pOH = 14 ⇒ pOH = 14 - pH = 14 - 12.05 = 1.95

pOH = -log [OH⁻] ⇒ [OH⁻] = [tex]10^{-pOH}[/tex]= [tex]10^{1.95}[/tex]= 0.0112 M ≅ 0.01 M

Answer:

0.0112

Explanation:

They said that was the answer.