Answer: ΔH°f of gaseous nitrogen monoxide is 148.0 kJ/mol
Explanation:
The balanced chemical reaction is,
[tex]NO(g)+\frac{1}{2}O_2(g)\rightarrow NO_2(g)[/tex]
The expression for enthalpy change is,
[tex]\Delta H_{rxn}=\sum [n\times \Delta H_f(product)]-\sum [n\times \Delta H_f(reactant)][/tex]
[tex]\Delta H_{rxn}=[(n_{NO_2}\times \Delta H_f_{NO_2})]-[(n_{O_2}\times \Delta H_f_{O_2})+(n_{NO}\times \Delta H_f_{NO})][/tex]
where,
n = number of moles
[tex]\Delta H_{O_2}=0[/tex] (as heat of formation of substances in their standard state is zero
Now put all the given values in this expression, we get
[tex]-114.14=[(1\times 33.90)]-[(\frac{1}{2}\times 0)+(1\times \Delta H_f{NO})][/tex]
[tex]\Delta H_f{NO}=148.0kJ/mol[/tex]
Therefore, ΔH°f of gaseous nitrogen monoxide is 148.0 kJ/mol
Fill in the blank.
5.22x10^-3 = [? ]x 10^-2
Answer:
?=0.522
Explanation:
5.22*10^-3=?*10^-2
5.22*0.01=?*0.1
0.522=?
This is my first time answer question, thx!
Answer:
0.522
Explanation:
What intermolecular forces are present among molecules in dimethyl ether, CH3OCH3?
a) London forces only
b) hydrogen bonding only
c) both London dispersion forces and hydrogen bonding
d) both London dispersion forces and dipole-dipole forces
Answer:
London forces only
Explanation:
Dimethyl ether is a nonpolar organic compound. Remember that for nonpolar organic substances, London forces are the primary intermolecular forces present.
Since dimethyl ether is a nonpolar organic compound, then it has London forces as its major intermolecular force. Intermolecular forces hold molecules of a substance together in a given state of matter.
A sample of metal has a mass of 21.17 g, and a volume of 7.98 mL. What is the density of this metal?
density:
Answer: 2.652882206 but it depends on how you round it so I would say 2.65 or 2.7 g/mL
Explanation: Density is mass divided by volume
Which list includes all the steps of a descriptive investigation?
A. Asking questions, making observations, collecting data, and
forming a conclusion
B. Asking questions, making observations, collecting data,
comparing, and forming a conclusion
C. Asking questions, making observations, and overcoming
limitations
D. Asking questions, making observations, experimenting, analyzing
data, and forming a conclusion
Answer:
A
Explanation:
Consider the reaction: 4HCl(g) + O2(g)2H2O(g) + 2Cl2(g) Using standard absolute entropies at 298K, calculate the entropy change for the system when 2.23 moles of HCl(g) react at standard conditions. S°system = J/K
Answer:
[tex]\mathbf{\Delta \ S^0 \ system \simeq -71.862 \ J/K}[/tex]
Explanation:
The chemical equation for the reaction is given as:
[tex]\mathsf{4 H Cl _{(g)} + O_{2(g)} \to 2H_2O _{(g)} + 2Cl_{2(g)}}[/tex]
the entropy change in the system can be calculated as follows:
[tex]\Delta S^0 \ system = \Delta S(products) - \Delta S (reactants)[/tex]
[tex]\Delta S^0 \ system = (2 \times \Delta S(H_2O )+2 \times \Delta S(Cl_2 ) ) - (4 \times \Delta S (HCl) + 1 \times \Delta S (O_2))[/tex]
From the tables; the entropy values where obtained.
∴
[tex]\Delta S^0 \ system = (2 \times(188.8 \ J/K )+2 \times ( 223.1 \ J/K )) - (4 \times \ ( 186.9 \ J/K ) + 1 \times ( 205.1 \ J/K ))[/tex]
[tex]\Delta S^0 \ system = (377.6 \ J/K +446.2 \ J/K )) - (747.6\ J/K ) + 205.1 \ J/K ))[/tex]
[tex]\Delta S^0 \ system = (377.6 \ J/K +446.2 \ J/K - 747.6\ J/K - 205.1 \ J/K )[/tex]
[tex]\Delta S^0 \ system = (-128.9 \ J/K )[/tex]
i.e the entropy change in the system when 4 moles of HCl is used = -128.9 J/K
∴
when 2.23 moles of HCl is used, Then,
[tex]\Delta \ S^0 \ system = \dfrac{-128.9 \ J/K }{4 \ mol } \times 2.23 \ mol[/tex]
[tex]\Delta \ S^0 \ system = -32.225 \ J/K \times 2.23[/tex]
[tex]\Delta \ S^0 \ system = -71.86175 \ J/K[/tex]
[tex]\mathbf{\Delta \ S^0 \ system \simeq -71.862 \ J/K}[/tex]
write about about who wants make lunch for himself
Answer:
Make your question clear friend
Explanation:
...
Answer:
A grown man when living single will make lunch by himself for himself
Explanation:
Convert a speed of 641 cm/s641 cm/s to units of inches per minute. Also, show the unit analysis by dragging components into the unit‑factor slots.
Answer:
[tex]15141.7\frac{in}{min}[/tex]
Explanation:
Hello,
In this case, by knowing that one inch equals 2.54 centimetres and 1 minute equals 60 seconds, the required velocity in inches per minute turns out:
[tex]641\frac{cm}{s}*\frac{1in}{2.54cm}*\frac{60s}{1min}}\\\\15141.7\frac{in}{min}[/tex]
Best regards.
An aluminum plate is 78 cm wide and 35 cm long. The mass of the plate is 44,226 g. Determine its thickness. [The density of lead is 2.70g/cm^3]
Answer:
i try to solve it for you, and i aplode a similer question for you
Explanation:
What change would you expect on the rate of the reaction of ethanol with 2-iodo-2-methylbutane if the nucleophile concentration is halved by adding diethyl ether as an inert solvent and the alkyl halide concentration is unchanged
Answer:
The rate of reaction is unchanged
Explanation:
The rate of reaction of tertiary alkyl halides with a nucleophile is independent of the nucleopohile concentration but depends only on the initial concentration of the alkyl halide since tertiary alkyl halides reacts via SN1 mechanism.
The nucleophile concentration does not come into the rate equation for the reaction hence any change in its concentration is inconsequential in determining the overall rate of reaction, hence the rate of reaction is unchanged when the nucleophile concentration is halved.
Acetic acid is a weak acid with a pKa of 4.76. What is the concentration of acetate in a buffer solution of 0.2M at pH 4.9. Give your answer in M but as a numeral only to 2 decimal places.
Answer:
[tex][base]=0.28M[/tex]
Explanation:
Hello,
In this case, by using the Henderson-Hasselbach equation one can compute the concentration of acetate, which acts as the base, as shown below:
[tex]pH=pKa+log(\frac{[base]}{[acid]} )\\\\\frac{[base]}{[acid]}=10^{pH-pKa}\\\\\frac{[base]}{[acid]}=10^{4.9-4.76}\\\\\frac{[base]}{[acid]}=1.38\\\\[/tex]
[tex][base]=1.38[acid]=1.38*0.20M=0.28M[/tex]
Regards.
A higher temperature of fresh concrete results in a __________ hydration of cement.
Answer:
more rapid
Explanation:
A higher temperature of fresh concrete results in a more rapid hydration of cement. This causes reduction in the setting time of the cement, also known as accelerated setting of the cement.
It also reduces the workability of the concrete; as it makes the movement of aggregates harder by reducing the lubricating effect of the cement.
A student has a cube that has a mass of 5.5g and a volume of 4.10 cm3. What substance does he have?
Answer:
1- d= m/v d=540/200 d=2,7 g/cm
Explanation:
Answer:
BELOW
Explanation:
[tex]Density = \frac{Mass}{Volume}\\ \\D=?\\mass = 5.5g\\volume = 4.10\\\\D = \frac{5.5}{4.10} \\\\Density = 1.34[/tex]
What volume of H2 could be produced at a temperature of 35 oC and a pressure of 769 torr by the reaction of 2.82 g of aluminum with hydrochloric acid?
Answer:
3.9 L of H2.
Explanation:
We'll begin by calculating the number of mole in 2.82 g of aluminium, Al.
This is illustrated below:
Mass of Al = 2.82 g
Molar mass of Al = 27 g/mol
Mole of Al =?
Mole = mass /Molar mass
Mole of Al = 2.82 / 27
Mole of Al = 0.104 mole
Next, we shall write the balanced equation for the reaction. This is given below:
2Al + 6HCI —> 2AlCl3 + 3H2
From the balanced equation above,
2 moles of Al reacted with 6 moles of HCl to produce 3 moles of H2.
Next, we shall determine the number of mole H2 produced by reacting 0.104 mole of Al.
This is illustrated below:
From the balanced equation above,
2 moles of Al reacted to produce 3 moles of H2.
Therefore, 0.104 mole of Al will react to produce = (0.104 x 3)/2 = 0.156 mole of H2.
Therefore, 0.156 mole of H2 was produced from the reaction.
Finally, we shall determine the volume of H2 produced by using the ideal gas equation as shown below:
Number of mole (n) of H2 = 0.156 mole
Pressure (P) = 769 torr = 769/760 = 1.01 atm
Temperature (T) = 35°C = 35°C + 273 = 308 K
Gas constant (R) = 0.0821 atm.L/Kmol
Volume (V) of H2 =?
PV = nRT
1.01 x V = 0.156 x 0.0821 x 308
Divide both side by 1.01
V = (0.156 x 0.0821 x 308) /1.01
V = 3.9 L
Therefore, 3.9 L of H2 were produced from the reaction.
What color would the cyanidin indicator turn in an acidic solution?
Answer:
it turns red in colour.
Explanation:
Post Lab Questions:
1. If you need to measure the volume of a 1.0 mL sample of solution would a 100 mL
graduated cylinder be appropriate? Why or why not?
Answer:
No.
Explanation:
Graduated cylinder is an instrument in chemistry used to measure approximate volumes of liquids. But you can't make volumetric analysis with these instruments because are not accurate as enough.
In chemistry, the measure of a sample must be accurate because you work with a sample to know which sample is and which is its purity. For that reaseon, graduated cylinder in not appropriate to measure 1.0mL of a sample. You must use PIPETTES.
Using what you know of map making terms and concepts and word parts, define hemisphere in your own words.
Answer:
The Earth is divided into two halves by the prime meridian, forming two half spheres divided vertically. The Earth is also divided into two halves by the equator, creating two half spheres divided horizontally.
Explanation:
I took it on edge ( :
Choose all of the given components that should not be included in a Materials and Methods/Experimental section of a research article. the conclusions that can be made from the data taken in the research project figures that include the data collected in the research project why the particular instruments were used to conduct the research the claims that the author wants to make regarding the research the types of instruments and devices used to conduct the research tables of data identifying the amount of each reactant in the research project tables of data identifying the amount of product formed by chemical reactions being studied
Answer:Im not sure ABT THIS ONE
Explanation:
27. The unit of volume in the metric system is the liter,
which consists of 1000 milliliters. How many liters or
milliliters is each of the following common English
system measurements approximately equivalent to?
a. a gallon of gasoline
b. a pint of milk
c. a cup of water
Liters and millilitres are the most common units of volume.
The volume equal to a gallon of gasoline is 3785 m L which is equal to 3.785 L.
The volume equal to pint of milk is 473...
A a cup of water is 0.24 L
Which of the following represents an electron configuration that corresponds to the valence electrons of an element for which there is an especially large jump between the second and third ionization energies?
A. [tex]ns^2[/tex]
B. [tex]ns^2np^1[/tex]
C. [tex]ns^2np^2[/tex]
D. [tex]ns^2np^3[/tex]
Answer:
C . ns²np²
Explanation:
According to this configuration the outermost orbit has 2 electrons in p and 2 electrons in s . After first ionization from p orbital involving energy E₁ , second ionisation from p is possible with E₂ energy . E₂ will be greater than E₁ .
But after second ionisation , there is no electron in p orbital . Hence the third ionisation is possible when we extract electron from s orbital . The difference in the ionisation energy of s and p is quite large . Hence third ionisation will involve much greater energy .
Hence third ionisation energy will be much larger than the second ionisation energy or
E₃ >>> E₂ .
Hence option ( C ) is correct .
The electron configuration that corresponds to the valence electrons of an element for which there is an especially large jump between the second and third ionization energies is ns2
Ionization energy is the energy required for the loss of an electron from an atom. The ionization energy is a periodic trend that decreases down the group but increases across the period.
A large jump occurs when the first electron is removed from an inner shell. If we look at the options, we will discover that the electron configuration that corresponds to the valence electrons of an element for which there is an especially large jump between the second and third ionization energies is a configuration in which there are two valence electrons. This happens to be ns2.
Learn more: https://brainly.com/question/12108425
A 0.530 m aqueous solution of KBr has a total mass of 61.0 g. What masses of solute and solvent are present? g
Answer:
[tex]m_{solute}=3.62g\\\\m_{solvent}=57.38g[/tex]
Explanation:
Hello,
In this case, since the given concentration is molality, we have:
[tex]m=\frac{mol_{solute}}{mass_{solvent}}[/tex]
Whereas the mass of the solvent (water for aqueous solution) is given in kg. Moreover, since the total mass of the solution is 61.0 g, one could write:
[tex]m_{solute}+m_{solvent}=61.0h\\\\m_{solvent}=61.0g-m_{solute}[/tex]
Which is replaced in the definition of molality:
[tex]m=\frac{mass_{solute}*\frac{1mol}{119g} }{(61.0g-m_{solute})*\frac{1kg}{1000g} }\\\\0.530m=\frac{8.4mass_{solute}}{61.0-mass_{solute}}[/tex]
Thus, solving for the mass of solution we obtain:
[tex]mass_{solute}=3.62g[/tex]
Therefore, the mass of the solvent is:
[tex]m_{solvent}=61.0g-3.62g\\\\m_{solvent}=57.38g[/tex]
Best regards.
What is the molarity (M) of .5 liter of a solution that has 205 g of NaCl dissolved in it?
Answer:
Molarity = 7 mol / LExplanation:
Since the mass of NaCl and it's volume has been given we can find the molarity by using the formula
[tex]C = \frac{m}{M \times v} [/tex]where
C is the molarity
m is the mass
M is the molar mass
v is the volume
From the question
v = 0.5 L
m = 205 g
We must first find the molar mass and then substitute the values into the above formula
M( Na) = 23 , M( Cl) = 35.5
Molar mass of NaCl = 23 + 35.5 =
58.5 g/mol
So the molarity of NaCl is
[tex]C = \frac{205}{0.5 \times 58.5} \\ C = \frac{205}{29.25} [/tex]
C = 7.00854
We have the final answer as
Molarity = 7 mol / LHope this helps you
Which of the following pure liquids is the best solvent for sodium fluoride?a. CCl4b. C2C6c. HCld. BCl3e. PCl5
Answer:
HCl
Explanation:
The best solvent for NaF is a polar liquid. The only liquid having a significant dipole moment among the options is HCl due to the large electro negativity difference between hydrogen and chlorine.
The polar solvent can interact with the NaF via its dipoles such that the NaF dissolves due to ion-dipole interaction.
electromagnetic radiation with _______ wavelengths is called ultraviolet light
Answer:
10nm
Explanation:
Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency of approximately 30 PHz) to 400 nm (750 THz), shorter than that of visible light but longer than X-rays.
1 mole of ribose (C5H10O5(s)) has a greater entropy than 1 mole of sucrose (C12H22O11(s)) True or false
Answer:
False
Explanation:
Hello,
In this case, it is possible to substantiate that the statement is false, since the entropy of sucrose is greater than the entropy of ribose due to the fact that molar mass of the sucrose (342 g/mol) is greater than the molar mass of ribose (150 g/mol) and the general rule states that the greater the molar mass the greater the entropy.
Best regards.
Consider the following reaction
2 N2 (g) + O2 (g) —-> 2 N2O (g) FinalH = + 163.2 kJ/mol
b) How much heat is required to produce 25.0 g of N2O by this reaction? Show all calculations.
Answer:
92.72 kJ
Explanation:
2 N₂ (g) + O₂ (g) —-> 2 N₂O
According to question , one mole of N₂O requires 163.2 kJ of heat
Molecular weight of N₂O = 44 gm
25 g N₂O = 25 / 44 mole
25 / 44 mole will require 163.2 x 25 / 44 kJ
= 92.72 kJ
Perform the given operation and report the answer with the appropriate number of significant figures. 4.910 km - 0.08 km = ?
Answer:
4.83 km
Explanation:
Let's consider the following subtraction.
4.910 km - 0.08 km
For an addition or a subtraction, the rule for significant figures is as follows: limit the reported answer to the rightmost column that all numbers have significant figures in common, in this case, 2 figures after the decimal point.
4.910 km - 0.08 km = 4.83 km
Can scientific ideas ever change?
Answer:
Yes Scientific ideas change over time as our evidence improves.
Explanation:
A scientific idea is an explanation for how something works, or the truth about some aspect of the world, that was figured out using the scientific process. ... Scientific ideas change over time as our evidence improves. The more experiments we do, and the more data we collect, the better our scientific ideas become.
Answer:
Yes scientific ideas can change...That's why they are called ideas so it may be right or wrong... ideas are just guesses that you consider may work or not.... I hope this helps you
Consider the reaction 5P4O6 + 8I2 4P2I4 + 3P4O10. How many grams of iodine must be added to 7.15 g of P4O6 to have a 5.00 % excess of iodine?
Answer:
You must add 13.86g of I₂
Explanation:
In the reaction:
5 P₄O₆ + 8I₂ → 4P₂I₄ + 3P₄O₁₀
5 moles of P₄O₆ reacts with 8 moles of I₂.
First, we need to determine how many moles of I₂ reacts completely with 7.15g of P₄O₆ (Molar mass: 219.88g/mol, thus:
7.15g P₄O₆ * (1mol / 219.88g) = 0.0325 moles P₄O₆.
Using the chemical reaction, the moles of I₂ that reacts are:
0.0325 moles P₄O₆ * ( 8 moles I₂ / 5 moles P₄O₆) = 0.0520 moles of I₂ react completely.
As molar mass of I₂ is 253.81g/mol, the mass of I₂ that reacts completely is:
0.0520 moles of I₂ * (253.81g / mol) =
13.2g of I₂.
As you must add 5.00% of excess:
13.2g + 5%13.2g =
You must add 13.86g of I₂
Distillation is a method that depends on differences in the boiling points of liquids to separate the components of a liquid mixture. Explain why you would separate a homogeneous mixture of two miscible liquids in this way but not a mixture of two immiscible liquids.
Explanation:
for immiscible liquids it is quite easy to separate and the separating funnel can be used but for miscible liquid they form a single entity and separating them is quite impossible if the differences in temperature is not considered,so in distillation the one with lower boiling point evaporates out living behind the one with high boiling point
can anyone explain it to me, please?
Answer:
2×10² cg
Explanation:
We'll begin by converting each of the above to the same unit of measurement.
In this case, we shall convert each of the above to kg. This can be obtained as follow:
Conversion of cg to kg
1 cg = 1×10¯⁵ Kg
Therefore,
2×10² cg = 2×10² × 1×10¯⁵
2×10² cg = 0.002 kg
Conversion of dg to Kg
1 dg = 1×10¯⁴ kg
Therefore,
10 dg = 10 × 1×10¯⁴
10 dg = 0.001 kg
Conversion of mg to kg.
1 mg = 1×10¯⁶ Kg
Therefore,
2×10² mg = 2×10² × 1×10¯⁶
2×10² mg = 0.0002 kg
Conversion of ng to kg
1 ng = 1×10¯¹² kg
Therefore,
1×10⁵ ng = 1×10⁵ × 1×10¯¹²
1×10⁵ ng = 0.0000001 Kg
Summary
1. 2×10² cg = 0.002 kg
2. 10 dg = 0.001 kg
3. 2×10² mg = 0.0002 kg
4. 0.001 kg
5. 1×10⁵ ng = 0.0000001 Kg
From the above calculation, 2×10² cg is the highest mass.