Question: Potassium hydrogen phthalate is a solid, monoprotic acid frequently used in the laboratory to standardize strong base solutions. It has the unwieldy formula of KHC8H4O4. This is often written in shorthand notation as KHP. Of 5.06 grams of KHP are needed to exactly neutralize 35.3 mL of a barium hydroxide solution, what is the concentration of the base solution?
Explanation and answer:
2KHP + Ba(OH)2 ---> 2H2O + Ba(KP)2
you need 2 moles of KHP to neutralise 1 mole of Ba(OH)2
moles KHO = mass / molar mass
= 2.43 g / 204.22 g/mol
= 0.0118989 mol
moles Ba(OH)2 = 1/2 x moles KHP
= 0.005949 mol
Molarity Ba(OH)2 = moles / Litres
= 0.005949 mol / 0.0213 L
= 0.279 M (3 sig figs)
What energy transformation is found in an electric motor?
Answer:
electrical energy is converted into mechanical energy.
Explanation:
An electric motor contains a permanent magnet and an electromagnet. As the poles of the electromagnet and the permanent magnet constantly repel each other, the electric motor makes a rotational motion. The increase in current or the increase in power of the magnet causes the electric motor to rotate faster.
. -9 + 6 - (-2)
Answers?
Answer:
-9+6-(-2)
-9+6+2
-9+8
-1 is the answer
Explanation:
You found that the unknown metal has a specific heat capacity close to, for example, that of silver [c=234J/(kg⋅K)]. Let's compare silver to other known materials and see whether your results make sense. Imagine you have 1 kg of each of the substances listed below. If the same amount of heat Q is added to each, which substance will undergo the largest change in temperature ΔT? Assume that no substance experiences a phase change. Rank the samples from largest to smallest change in temperature.
a. c= silver/ 234J(kg/K)
b. c= water/ 4190 J(kg/K)
c. c= glass/ 754J/(kg.K)
Answer:
a. c= silver/ 234J(kg/K) > b. c= water/ 4190 J(kg/K) > c. c= glass/ 754J/(kg.K)
Explanation:
Hello.
In this case, since the heat resulting from the temperature change for an specified amount of a substance is defined via:
[tex]Q=mCp\Delta T[/tex]
Since the specific heat is related to amount of energy required to raise the temperature of 1 kg of a substance by 1 °C, we can infer that the higher the specific heat, the higher the required energy as they are in a directly proportional relationship. Moreover, since the specific heat and the change in temperature are in an inversely proportional relationship, we can infer that the higher the specific heat, the lower the temperature change, therefore, we can rank the substances follows:
a. c= silver/ 234J(kg/K) > b. c= water/ 4190 J(kg/K) > c. c= glass/ 754J/(kg.K)
It means that silver will produce the largest temperature change, next water and finally glass since silver has the smallest specific heat next water and finally glass.
Best regards.
Which scientific term names rocks formed from magma?
A. Intrusive
B. Lava
C. Gabbro
D. Extrusive
Answer:
A Intrusive
Explanation:
I go to K12 and they say that's the answer
The protein lysozyme unfolds at a transition temperature of 75.5°C, and the standard enthalpy of transition is 509 kJ mol-1. Calculate the entropy of unfolding of lysozyme at 25.0°C, given that the difference in the constant-pressure heat capacities upon unfolding is 6.28 kJ K-1 mol-1 and can be assumed to be independent of temperature. Hint: Imagine that the transition at 25.0°C occurs in three steps: (i) heating of the folded protein from 25.0°C to the transition temperature, (ii) unfolding at the transition temperature, and (iii) cooling of the unfolded protein to 25.0°C. Because the entropy is a state function, the entropy change at 25.0°C is equal to the sum of the entropy changes of the steps.
Answer:
0.4774 KJ/K.mol
Explanation:
We are told that the transition at 25.0°C occurs in three steps. Steps i, ii and iii.
Thus;
the entropy of unfolding of lysozyme = ΔS_i + ΔS_ii + ΔS_iii
Now,
C_p,m(unfolded protein) = C_p,m(folded protein) + 6.28 kJ/K.mol
Now, for the first process, ΔS_i is given as;
ΔS_i = C_p,m × In(T2/T1)
We are given;
T1 = 25°C = 25 + 273.15K = 298.15 K
T2 = 75.5°C = 75.5 + 273.15 K=348.65 K
Thus;
ΔS_i = C_p,m × In(348.65/298.15)
Now, for the third process, ΔS_iii is given as;
ΔS_iii = (C_p,m + 6.28 kJ/K.mol) × In(T1/T2)
Thus;
ΔS_iii = (C_p,m + 6.28 kJ/K.mol) × In(298.15/348.65)
Now, we don't know C_pm. So, we have to find a way to eliminate it. We will do it by rewriting In(298.15/348.65) in such a way that when ΔS_iii is added to ΔS_i, C_p,m will cancel out. Thus;
In(298.15/348.65) can also be written as;
In(348.65/298.15)^(-1) or
- In(348.65/298.15)
Thus;
ΔS_iii = - [(C_p,m + 6.28 kJ/K.mol) × In(298.15/348.65)]
Now, let's add ΔS_iii to ΔS_i to get;
ΔS_i + ΔS_iii = [C_p,m × In(348.65/298.15)] + [(-C_p,m - 6.28 kJ/K.mol) × In(348.65/298.15)]
ΔS_i + ΔS_iii = [C_p,m × In(348.65/298.15)] - [C_p,m × In(348.65/298.15)] - [6.28In(348.65/298.15)]
First 2 terms will cancel out to give;
ΔS_i + ΔS_iii = -6.28In(348.65/298.15)
ΔS_i + ΔS_iii = -0.9826 KJ/K.mol
Now,for process ii;
ΔS_ii = standard enthalpy of transition/Transition Temperature
Thus;
ΔS_ii = (509 KJ/K.mol)/348.65
ΔS_ii = 1.46 KJ/K.mol
Thus;
the entropy of unfolding of lysozyme = ΔS_i + ΔS_ii + ΔS_iii = -0.9826 + 1.46 = 0.4774 KJ/K.mol
The first reaction in the Ostwald process for the production of nitric acid involves the combustion of ammonia
4NH3(g)+5O2(g)=4NO(g)+6H2O(g)
a) Estimate ΔH^o (in kJ) for this reaction using average bond energies.
b) Calculate ΔH^o (in kJ) for this reaction using standard heats of formation.
c) Briefly explain why the value for ΔH^o, calculated using average bond energies, is only considered to be an estimate of the standard enthalpy change for the reaction
Answer:
Explanation:
Given that;
The chemical equation for the reaction is:
[tex]\text {4NH}_3(g) +\text {5O}_2(g) }[/tex] ↔ [tex]\text {4NO}(g) +\text {6H}_2O}(g) }[/tex]
a). [tex]\Delta H^0 = \sum \Delta H^0_{reactant \ bonds \ broken} + \sum \Delta H^0_{product \ bonds \ formed}[/tex]
Using average bond energies;
For Bonds broken, we have:
4 × 3 N - H = 12 mol × 391 kJ/mol = 4692 kJ
5 × O = O = 5 mol × 498 kJ/mol = 2490 kJ
[tex]\mathbf{ \sum \Delta H^0_{reactant \ bonds \ broken} }[/tex] = 7182 kJ
For Bonds formed, we have:
4 × N = O = 4 mol × - 607 kJ/mol = -2428 kJ
6 × 2 O - H = 12 mol × - 467 kJ/mol = - 5604 kJ
[tex]\mathbf{ \sum \Delta H^0_{product \ bonds \ formed} }[/tex] = - 8032 kJ
Therefore;
[tex]\mathbf{ \Delta H^o = 7182 kJ + (- 8032 \ kJ)}[/tex]
[tex]\mathbf{ \Delta H^o =-850 \ kJ}[/tex]
b) Using Standard heats of formation;
[tex]\Delta H^0 = \sum m \Delta H^0_f (products) = \sum n \Delta H^0_f (reactants)[/tex]
[tex]\Delta H^0 = [ 4 \ mol \times \Delta H^0_f \ (NO(g)) + 6\ mol \times \Delta H^0_f(H_2O)] - [ 4 \ mol \times \Delta H^0_f \ (NH_3(g)) + 5 \ mol \times \Delta H^0_f \ (O_2)][/tex]
[tex]\Delta H^0 = [ 4 \ mol \times90.29 \ kJ/mol + 6\ mol \times -241.826 \ kJ/mol - [ 4 \ mol \times-45.9 \ kJ/mol + 5 \ mol \times 0][/tex]
[tex]\mathbf{\Delta H^0 = -906.196 \ kJ}[/tex]
c) The value of ΔH^o, calculated using average bond energies, is only considered to be an estimate of the standard enthalpy change for the reaction because there is a premise in the calculation that all the bonds broken in the reactant and all bonds are formed in products. Meanwhile, only little bonds are broken, and only little bonds are formed during the reaction.
_____ CH 4 + _____ O 2_____ CO 2+ H 2 O
Answer:
Carbon dioxide and oxygen
Explanation:
What mass of cobalt contains the same number of atoms as 57.0 g fluorine
Answer:
This is a chemistry problem i'm having some issues with. I have a test tomorrow and need all the help I can get.
What I thought to do was first figure out the atoms of 57.0g F, which I got 2x10^24.
Then I tried to convert it into grams Co.
Would I just divide it by 6.022x10^23 and then multiply by the molar mass of Co?
Is the answer 195.7g?
Thanks!
Explanation:
The mass of Cobalt that contains the same number of atoms in 57 g of fluorine is 177 g
We'll begin by calculating the number atoms in 57 g of fluorine. This can be obtained as follow:
From Avogadro's hypothesis,
1 mole of F = 6.02×10²³ atoms
But,
1 mole of F = 19 g
Thus,
19 g of F = 6.02×10²³ atoms
Therefore,
57 g of F = [tex]\frac{57 * 6.02*10^{23} }{19}\\\\[/tex]
57 g of F = 1.806×10²⁴ atoms
Finally, we shall determine the mass of Cobalt that contains 1.806×10²⁴ atoms. This can be obtained:
From Avogadro's hypothesis,
6.02*10²³ atoms = 59 g of Co
Therefore,
1.806×10²⁴ atoms = [tex]\frac{59 * 1.806 *10^{24} }{6.02*10^{23} }\\\\[/tex]
1.806×10²⁴ atoms = 177 g of Co
Thus, we can conclude that 177 g of Cobalt (Co) contains the same number of atoms in 57 g of fluorine
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which objects would have a greater gravitational force between them, Objects A and B, or Objects B and C? PLEASE HELPPP
Answer:
hmm:
Explanation:
Unless I am crazy, there should be an image attached to this. But, you can use this formula:
[tex]F = G\frac{m_1m_2}{r^2}[/tex] where F is the force, G is a constant, m1 and m2 are the masses of the objects, and r is the distance between the objects.
What is the predominant intermolecular force in the liquid state of each of these compounds: methanol (CH3OH), carbon tetrafluoride (CF4), and hydrogen chloride (HCl)?
Answer:
Throughout the liquid state, certain forces are encountered by the aforementioned molecules:
Explanation:
CH₃OH: Combining with hydrogen. That's also since O is a very electronegative atom here between O as well as H including its molecule. These powers, with H, propagate between O, F as well as N. That's the main power, then.CF₄: F will establish hydrogen bonds, but it is not bound to H in this situation, so this may not be the primary power. Throughout this situation, owing to its tetrahedral structure, it does not have a net dipole. It then just has dispersion powers, which are sometimes referred to as van der Waals either London forces. HCl: powers of dipole-dipole as well as London dispersion.The liter is defined as
a
1000 c3.
b
1000 m3.
c
1000 cm3.
d
1000 g3.
Answer:
C
Explanation: I mL = 1 cm3 and 1 L = 1000 mL so 1 L - 1000 cm3
Answer:
d
Explanation:
What is the resistance of a circuit with 120 volts and 30 amps.
Answer:
40
Explanation:
120/30=40
how to synthesize N-methylpropanamide with a acid anhydride
Answer:
See attached picture.
Explanation:
Hello.
In this case, since the synthesis of amides via anhydride requires its reaction with the N-radical primary amine, as it is required to yield N-methylpropanamide, the reactants must be propanoic anhydride and methylamine in order to yield the aforementioned amide as well as propanoic acid as a side product.
This reaction is shown on the attached picture.
Best regards.
What is the chemical formula for the compound formed between chromium(III) and the bromate ion?
Answer:
The chemical formula is Cr(BrO3)3.
The chemical formula formed between chromium (III) and bromate ion is Cr(BrO3)2.
What is the chemical formula?A chemical formula is an formula for the atoms in compound which are arranged in a fixed proportion.
The chemical formula of salt is NaCl. The chemical formula of sodium bicarbonate is NaHCO3. The chemical formula of chromium bromate is Cr(BrO3)2.
The molecular mass of chromium bromate is 435. 7027. The valency of chromium in chromate ion is 2. The atomic number of chromium is 24. The atomic number of bromine is 35. Bromine contain seven valence electrons.
Therefore, The chemical formula formed between chromium (III) and bromate ion is Cr(BrO3)2.
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How many atoms are in 55g of H2SO4?
3.4 atoms
2.58 atoms
04.14 atoms
98.1 atoms
Answer: 3.4 atoms
Explanation: hope this helps you!!
Name:
1. Draw the Lewis Dot diagram for the molecule AB2C. Element A has 4 valence electrons
and requires a full octet. Element B has 1 valence electron, but only gets 2 valence
electrons to have a full outer shell. Element C has 6 valence electrons and needs
to
have 8 valence electrons for a full octet.
Identify the chane name for the molecule
Answer:
See attached picture and explanation.
Explanation:
Hello!
In this case, given the instruction on the molecule, we can infer that A is the central atom as it must have a full octet which is reached via one bond with each B atom. Moreover, via a double bond with C, both A and C are able to have the required full octet as shown on the attached picture.
For the name, it looks like the formaldehyde ([tex]CH_2O[/tex]) which has two single-bonded hydrogen atoms and one double-bonded oxygen atom in order to have a full octet forth both carbon and oxygen.
Regards.
Alcohol and water are best separated from one another by
Answer:
fractional distillation
Explanation:
What best describes the dropping height of a ball that bounced back up to a height of 45 centimeters?
Less than 45 centimeters, as the ball transforms some of its thermal energy into potential energy
Greater than 45 centimeters, as the ball transforms some of its thermal energy into potential energy
Less than 45 centimeters, as the ball transforms some of its potential energy into thermal energy and sound energy
Greater than 45 centimeters, as the ball transforms some of its potential energy into thermal energy and sound energy
Answer:
less than 45 cm, as the ball transforms some of its potential eneregy to termal energy and sound energy
Two students are engaged in an argument about whether or not a plant can live independently inside of a sealed jar for up to two weeks by using energy from the sun and energy from the mitochondria to carry out all of its life processes.
Student A: The plant can live independent of other organisms such as animals, because it can obtain nutrients to grow, reproduce, make needed materials, and remove the waste on its own.
Student B: The plant only relies on other organisms, such as animals that produce the carbon dioxide needed to obtain nutrients to grow, reproduce, make needed materials, and remove waste.
Based on the diagram, which student's argument is BEST supported? Use evidence from the diagram to support your reasoning.
Answer:
where's the diagram?
Explanation:
the best answer is student A
What is the process that occurs when repeated freezing and thawing breaks apart rocks?
A- Erosion
B-Deposition
C-Physical Weathering
D- Chemical Weathering
11 POINTS!!!!!!! HURRYYY! PLEASE
Answer:
c
Explanation:
Physical Weathering is process that occurs when repeated freezing and thawing breaks apart rocks
what percent of earths carbon is stored in soil?
Answer:80%
Explanation:Total C in terrestrial ecosystems is approximately 3170 gigatons (GT; 1 GT = 1 petagram = 1 billion metric tons). Of this amount, nearly 80% (2500 GT) is found in soil (Lal 2008).
Under what categories of cells would the animal and plant cell fall
John eats a 1 lb steak, 8 chicken wings, a half pound of fries, potato salad, coleslaw,
and 6 slices of pizza at Food Emporium, his favorite restaurant. The waiter comes by
to offer John a slice of cake but he refuses because cake doesn't sound appetizing to
him although at any other time, John would have most likely ordered a slice of cake.
This is an example of which of the following phenomena.
O allesthesia
O Pteradactyl-like eating behaviors
O somatosensory simulation
O anorexia
The given example is a good description of the phenomena is:
D. AnorexiaAnorexia is an eating disorder which makes a person to feel that any extra food is going to cause him to become obese and because of this, he would reduce his intake of food.
As a result of this, they tend to get some health issues as a result of their refusal to eat certain foods or even eat at all. This is evident in the given example of John refusing to eat an extra slice of cake after having a huge meal at his favorite restaurant.
Therefore, the correct answer is option D
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Example of balanced force
It would be A since a balanced force would stay the same.
Knowing that the distances the truck traveled during each segment were 30, 45, 50, and 65 respectively, what was the total distance traveled by the truck?
Answer:
The distance the truck traveled is 190
Explanation:
I added 30, 45, 50, 65 together to get the total distance
1. What is the mass of the cart with a constant net force of 200N is exerted
to accelerate from rest to a velocity of 40m/s in 10 s.
A. 0.5 kg
C. 50 kg
B. 5 kg
D. 500 kg
Answer:
50
Explanation:
so you'll have to apply Newton's 2nd law which is F=ma and then substitute the values that you already have in the question as in, the force is 200 and you'll have to find the acceleration by working it out which is 4m/s² and then find the mass by dividing 200 by 4 so the actual mass is 50kg ✌️❤️
Taking into account the Newton's second law, the mass of the cart is 50 kg.
You have to know that Newton's second law states that this force will change the speed of an object because the speed and / or direction will change. These changes in velocity are called acceleration.
So, Newton's second law defines the relationship between force and acceleration mathematically. This law says that the acceleration of an object is directly proportional to the sum of all the forces acting on it and inversely proportional to the mass of the object.
Mathematically, Newton's second law is expressed as:
F= m×a
where:
F = Force [N] m = Mass [kg] a = Acceleration [m/s²]Acceleration relates the changes in velocity with the time in which they occur. So:
[tex]a=\frac{final velocity - initial velocity}{time}[/tex]
In this case:
F= 200 Nm= ?[tex]a=\frac{40 \frac{m}{s}-0\frac{m}{s} }{10 s} = 4 \frac{m}{s^{2} }[/tex]Replacing in the expression for Newton's Second Law:
200 N= m× 4 m/s²
Solving:
m= 200 N÷4 m/s²
m= 50 kg
Finally, the mass of the cart is 50 kg.
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brainly.com/question/23845187?referrer=searchResults brainly.com/question/13959891?referrer=searchResultstwo substances in a mixture differ in density and particle size. These properties can be used to
Answer:
(1) separate the substances
(2) chemically combine the substances
(3) determine the freezing point of the mixture
(4) predict the electrical conductivity of the mixture
Explanation:
Answer: I think the best answer from the choices listed above is option 1. Two substances in a mixture differ in density and particle size. These properties can be used to separate the substances. These properties can be manipulated in order to have a better separation between the two substances.
Copper has a density of 8.96 g/cm3. What is the mass of a piece of copper with a volume of 2.62 cm3?
Answer:
The answer is 23.48 gExplanation:
The mass of a substance when given the density and volume can be found by using the formula
mass = Density × volumeFrom the question
volume of copper = 2.62 cm³
density = 8.96 g/cm³
We have
mass = 8.96 × 2.62 = 23.4752
We have the final answer as
23.48 gHope this helps you
What are the materials Identify a cube
Answer:
If the prime factors of a number are grouped in triples of equal factors, then that number is called a perfect cube. In order to check whether a number is a perfect cube or not, we find its prime factors and group together triplets of the prime factors. If no factor is left out then the number is a perfect cube.
Explanation:
Which statement is correct about a sample of liquid water
The molecules in ice and liquid water have the same kinetic energy. Liquid water has a greater entropy than ice and the liquid water has a greater potential energy than ice. The correct option is D.
What is kinetic energy?Kinetic energy is the energy that an object or particulate has as a result of its motion.
When work, which converts energy, is performed on an object by applying a net force, the object accelerates and gains kinetic energy.
Potential energy is the energy that an object has as a result of its location in relation to other objects.
Potential energy is frequently associated with restoring forces such as a spring or gravity.
Ice and liquid water molecules have the very same kinetic energy. Liquid water has more entropy than ice, and it also has more potential energy than ice.
The correct answer is D.
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Your question seems incomplete, the complete question may be:
Correct statements about samples of ice and liquid water at 0∘ C include which of the following ?
(P) Molecules in ice and liquid water have the same kinetic energy.
(Q) Liquid water has a greater entropy than ice.
(R ) Liquid water has a greater potential energy than ice
A. P and Q onlyB. P and R onlyC. Q and R onlyD. P,Q and R