Answer:
Physical change are the temporary reversible change in which no new substance is formed.
Example: boiling of milk, melting of wax, cooling water,etc.
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.
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 ( :
What is the PH of sebacic acid ?
Answer:
Sebacic acid is a naturally occurring dicarboxylic acid with the formula (CH2)8(CO2H)2. It is a white flake or powdered solid. Sebaceus is Latin for tallow candle, sebum is Latin for tallow, and refers to its use in the manufacture of candles.
Explanation:
pls mark as brainliest!!!!!
Determine the pH of the following solutions, given their hydrogen ion concentration. a. [H+] = 10^-5 M
Answer:
pH = 5Explanation:
The pH of the solution can be found by using the formula
pH = - log [H+]
From the question
[H+] = 10^-5 M
Substitute the value into the above formula and solve for the pH
That's
[tex]pH = - log( {10}^{ - 5} ) [/tex]
We have the final answer as
pH = 5
Hope this helps you
Speed of light is 3.0x108 m/s. Convert speed of light unit into miles per hour (mi/s). 3.0x108 m/s =
mi/s
Report your answer in the format with correct sig figs:
5x1013
Given:
1 mile = 1.61 km
1 km = 1000 m
Explanation:
1 mile = 1.61 km and 1 km = 1000 m
The speed of light is [tex]3\times 10^8\ m/s[/tex]. We need to convert it into miles per hour.
1 m = (1/1000) km
[tex]3\times 10^8\ m=\dfrac{3\times 10^8}{1000}\\\\=3\times 10^5\ km[/tex]
1 km = (1/1.61) miles
[tex]3\times 10^5\ km =\dfrac{3\times 10^5}{1.61}\\\\=1.86\times 10^5\ \text{miles}[/tex]
So, [tex]v=1.86\times 10^5\ \text{miles/s}[/tex]
Hence, this is the required solution.
How much energy has your body used, in joules, if your health indicates the 450 Calories were burned during your workout? How many Calories are in a dinner containing 3.5 x 106 joules?
Answer:
107.55 J, 88.67 cal
Explanation:
1 Joule = 0.239 Calories
450 cal x 0.239 = 107.55 J
3.5 x 106 = 371
371 J = 371 x 0.239 cal
371 J = 88.67 cal
Janey loves this time of year because she loves eating marshmallow Peeps. One day, she eats ten peeps; 8 of them have a mass of 100 g, 1 of them has a mass of 150 g, and 1 of them has a mass of 200 g. What is the average mass of all the People that Jany ate? Show your work.
Answer:
115g
Explanation:
100*8=800
800+150+200=1150
1150/10=115
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
100 billion in scientific notation?
Answer: 1×10^11
Explanation:
concept to know: scientific notation must be written in the form of a × 10^b
where 0<a<10.
100 billion= 100,000,000,000
there are 11 zeros after 1
1 × 10^11
Hope this helps!! :)
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:
Calculate the molar concentration of HA (90.2 g/mol) in a solution that has a specific gravity of 1.24 and is 64% HNO3 (w/w).
Answer:
Explanation:
Hello,
In this case, considering the given specific gravity we are to compute the density of the 64% HNO3 solution:
[tex]\rho=1.24*1g/mL=1.24g/mL[/tex]
In such a way, since the given solution of nitric acid is 64 % by mass, we've got:
[tex]\frac{64gHNO_3}{100g\ solution}[/tex]
Thus, by using the previously computed density and the molar mass of HA (90.2 g/mol) we can compute the required molar concentration as follows:
[tex]M=\frac{(100g-64g)HA}{100g\ solution}*\frac{1.24g\ solution }{1mL \ solution}*\frac{1000mL\ solution}{1L\ solution}*\frac{1molHA}{90.2gHA} \\\\M=4.95M[/tex]
Regards.
Consider the two gaseous equilibria: The values of the equilibrium constants K 1 and K 2 are related by
The question is missing parts. The complete question is as follows.
Consider the two gaseous equilibria involving SO2 and the corresponding equilibrium constants at 298K:
[tex]SO_{2}_{(g)} + \frac{1}{2}O_{2}[/tex] ⇔ [tex]SO_{3}_{(g)}[/tex]; [tex]K_{1}[/tex]
[tex]2SO_{3}_{(g)}[/tex] ⇔ [tex]2SO_{2}_{(g)}+O_{2}_{(g)}; K_{2}[/tex]
The values of the equilibrium constants are related by:
a) [tex]K_{1}[/tex] = [tex]K_{2}[/tex]
b) [tex]K_{2} = K_{1}^{2}[/tex]
c) [tex]K_{2} = \frac{1}{K_{1}^{2}}[/tex]
d) [tex]K_{2}=\frac{1}{K_{1}}[/tex]
Answer: c) [tex]K_{2} = \frac{1}{K_{1}^{2}}[/tex]
Explanation: Equilibrium constant is a value in which the rate of the reaction going towards the right is the same rate as the reaction going towards the left. It is represented by letter K and is calculated as:
[tex]K=\frac{[products]^{n}}{[reagents]^{m}}[/tex]
The concentration of each product divided by the concentration of each reagent. The indices, m and n, represent the coefficient of each product and each reagent.
The equilibrium constants of each reaction are:
[tex]SO_{2}_{(g)} + \frac{1}{2}O_{2}[/tex] ⇔ [tex]SO_{3}_{(g)}[/tex]
[tex]K_{1}=\frac{[SO_{3}]}{[SO_{2}][O_{2}]^{1/2}}[/tex]
[tex]2SO_{3}_{(g)}[/tex] ⇔ [tex]2SO_{2}_{(g)}+O_{2}_{(g)}[/tex]
[tex]K_{2}=\frac{[SO_{2}]^{2}[O_{2}]}{[SO_{3}]^{2}}[/tex]
Now, analysing each constant, it is easy to see that [tex]K_{1}[/tex] is the inverse of [tex]K_{2}[/tex].
If you doubled the first reaction, it will have the same coefficients of the second reaction. Since coefficients are "transformed" in power for the constant, the relationship is:
[tex]K_{2}=\frac{1}{K_{1}^{2}}[/tex]
9.44 x 10^3 In standard form
Is HCL a pure substance? Look at me already asking chemistry questions! //!roll eyes emoji/2#/
Answer:
yes it is as it has a chemical formula which cannot be changed
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
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.
The following reaction is investigated: 2N2O(g) N2H4(g) <---> 3N2(g) 2H2O(g) Initially there are 0.100 mol of N2O and 0.25 mol of N2H4, in a 10.0-L container. If there are 0.059 mol of N2O at equilibrium, how many moles of N2 are present at equilibrium
Answer:
6.2 × 10^-2
Explanation:
Given the reaction:
------------2N2O(g) N2H4(g) <---> 3N2(g) 2H2O(g)
Initial: N2O = 0.1, N2H4 = 0.25-- 0 - - - - - 0
Then: N20 = -2x, N2H4= - x - - - +3x, +2x
Equ : 0.1 - 2x ; 0.25 - x ; +3x ; +2x
At equilibrium :
Add both:
N2O = 0.1 - 2x ;
N2H4 = 0.25 - x;
3N2 = 3x
2H2O = 2x
Moles of N2O at equilibrium = 0.059
Then;
0.1 - 2x = 0.059
-2x = 0.059 - 0.1
-2x = - 0.041
x = 0.041 / 2
x = 0.0205
Moles of N2 present at equilibrium ;
3N2 = 3x
3N2 = 3(0.0205)
= 0.0615
= 0.062 = 6.2 × 10^-2
calculate the ph of the solution resulting from the addition of 20 ml of 0.100 m naoh to 30 ml of 0.100 m hno 3
Answer:1.6989
Explanation:
The pH of the solution prepared by mixing NaOH and [tex]\rm HNO_3[/tex] has been 1.69.
The moles of NaOH can be given by:
Moles = Molarity × Volume (L)
Moles of NaOH = 0.1 M × 0.02 LMoles of NaOH = 0.002 mol
Moles of [tex]\rm HNO_3[/tex] = 0.1 M × 0.03 L
Moles of [tex]\rm HNO_3[/tex] = 0.003 mol
Since, [tex]\rm HNO_3[/tex] has been remaining in the solution after neutralization, the moles of [tex]\rm HNO_3[/tex] has been :
[tex]\rm HNO_3[/tex] = 0.003 - 0.002 mol
[tex]\rm HNO_3[/tex] = 0.001 mol.
The moles of [tex]\rm HNO_3[/tex] has been equivalent to the moles of hydrogen ion.
The hydrogen ion has been 0.001 mol.
The concentration of Hydrogen ions can be given by:
Hydrogen ion concentration = [tex]\rm \dfrac{Moles}{Volume(L)}[/tex]
Hydrogen ion concentration = [tex]\rm \dfrac{0.001}{0.03\;+\;0.02}[/tex]
Hydrogen ion concentration = 0.02 M.
pH can be defined as the negative log of the hydrogen ion concentration.
pH = - log ([tex]\rm H^+[/tex])
pH = - log (0.02)
pH = 1.69
The pH of the solution prepared by mixing NaOH and [tex]\rm HNO_3[/tex] has been 1.69.
For more information about the pH of the solution, refer to the link:
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What is the percent yield in a reaction between 42.6 g O2 and 49.2 g Al if 72.4 g of Al2O3 is produced?
Answer:
229%
Explanation:
The equation of the reaction is;
4Al(s) + 3O2(g) ----> 2Al2O3(s)
We must first determine the limiting reactant;
Number of moles of Al2O3 produced = mass/molar mass = 72.4g/101.96 g/mol = 0.71 moles
For Al
Number of moles reacted = mass/molar mass = 49.2g/27 g/mol = 1.8 moles
If 4 moles of Al yields 0.71 moles of Al2O3
1.8 moles of Al will yield 1.8 × 0.71/4 = 0.32 moles of Al2O3
For O2
Number of moles reacted = mass/molar mass = 42.6g/32g/mol = 1.33 moles
If 3 moles of O2 yields 0.71 moles of Al2O3
1.33 moles of O2 will yield 1.33 × 0.71/3 = 0.31 moles of Al2O3
Oxygen is the limiting reactant.
% yield = actual yield/ theoretical yield × 100/1
% yield = 0.71 moles/0.31 moles × 100
% yield = 229%
What does the aufbau principle suggest about electron configuration?
Electrons within the same atomic orbital have different spins.
Electrons occupy orbitals with the lowest energy first.
No more than two electrons can occupy the same atomic orbital.
Filled sublevels are more stable than partially filled sublevels.
Answer:
Electrons occupy orbitals with the lowest energy first.
Explanation:
The Aufbau Principle states that electrons will fill the atomic orbitals with the lowest energy levels first, before occupying others with higher energy levels.
For example, electrons will fill the 1s orbital before filling the 2s orbital.
Answer:
It is Filled sublevels are more stable than partially filled sublevels.
Explanation:
Just took the test and this was right.
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
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]
evidence and reasning on when puppies are going to be born
Answer:
Keep a close eye on her in case she starts giving birth to the next pup at the same time. A greenish/brown discharge may suggest a placenta has separated. If you see this, a puppy should be born within the next 2-4 hours.
Which of the changes are chemical changes?
Sugar is dissolved in water.
A warm soda bottle fizzes when opened.
The copper roof turns green over time.
Baking soda is dissolved in vinegar and bubbles form.
A fog appears on the windshield in cold weather.
Answer:
two of them are chemical changes
Explanation:
1.) the copper roof turns green over time: it forms a new substance which is the green deposit known as verdigris .
2.) baking soda is dissolved in vinegar and bubbles form: it forms a new substance which is carbon dioxide gas.
I hope it helps:)
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
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.
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.
What is the density of an object that has a volume of 26 mL and a mass of 52 g?
Answer:
Density = 2 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]Density = \frac{mass}{volume} [/tex]
From the question
mass = 52 g
volume = 26 mL
Substitute the values into the above formula and solve for the density
That's
[tex]Density = \frac{52}{26} [/tex]
We have the final answer as
Density = 2 g/mLHope this helps you
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 measurement represents the largest quantity?
A) 47.3 mg
B)
4.73 x
x 10-6 kg
C)
4.73 x 103 ug
D) 4730 ng
E)
4.73 x
x 10-4 g
Answer:
A
Explanation:
The measurement represents the largest quantity among the given options is 47.3 mg Hence, Option (A) is correct.
What is conversion factor ?
An arithmetical multiplier for converting a quantity expressed in one set of units into an equivalent expressed in another.
Therefore comparing all the four options it can be concluded that,The measurement represents the largest quantity among the given options is 47.3 mg Hence, Option (A) is correct.
Learn more about measurement here ;
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