Answers
The boiling point of water generally increases as the amount of impurities (which a solute like KCl technically can be thought of) dissolved increases. This relation can be quantified using the equation,
[tex]\Delta T_b = i \times K_b \times m[/tex]
where [tex]\Delta{T}_{b}[/tex] is the change in the water's boiling point (normally taken to be 100 °C), [tex]i[/tex] is the Van 't Hoff factor (the number of particles a single formula unit of the solute dissociates into in water), [tex]K_b[/tex] is the boiling point elevation constant, and [tex]m[/tex] is the molality (moles of solute/kilogram(s) of solvent) of the solution.
We are forming a solution by dissolving KCl in water. KCl is an electrolyte that, in water, will dissociate into K⁺ and Cl⁻ ions. So, for every formula unit, KCl, we obtain two particles. Thus, the Van 't Hoff factor, or [tex]i[/tex], will be 2.
The molality of the solution can be calculated by dividing the number of moles of KCl by the mass of water in kilograms. Since we have 1.00 kg of water, we would be dividing 0.75 mol KCl by 1, giving us a molality (m) of 0.75 m.
We aren't provided the boiling point elevation constant for water. Several authoritative sources give the value 0.512 °C/m, so we will adopt that as our [tex]K_b[/tex].
Note: m = mol/kg as used in this problem.
Plugging everything in,
[tex]\Delta T_b = i \times K_b \times m \\\Delta T_b = 2 \times 0.512 \text{ } \frac{^oC}{mol/kg} \times 0.75 \text{ } \frac{mol}{kg} \\\Delta T_b = 0.768 \text{ } \mathrm{ ^oC}[/tex]
As you can see, our change in boiling point is positive (the boiling point is elevated), and it is also quite modest. Taking 100 °C to be the boiling point of pure water, the boiling point of our solution would be 100 ⁰C + 0.768 ⁰C, or 100.768 ⁰C.
If we are considering significant figures, then we must give our answer to two significant figures (since 0.75 has two sig figs). We can regard the boiling point of water (100 ⁰C) as a defined value. Since our final answer is a sum, the boiling point of our solution to two significant figures would be 100.77 ⁰C.
Given:
Mol = 0.75Mass = 1.00 kgWe know,
Boiling point constant, Kb = 0.51The molality of the solution will be:
= [tex]\frac{Mole}{Mass}[/tex]
= [tex]\frac{0.75}{1}[/tex]
= [tex]0.75 \ m[/tex]
Now,
→ [tex]T_{solution}-T_{water} = Kb\times m\times i[/tex]
By putting the values, we get
[tex]= 0.51\times 0.75\times 2[/tex]
[tex]= 0.765[/tex]
Boiling point of water = 100°Chence,
Solution's boiling point will be:
→ [tex]T_{solution} = 100+0.765[/tex]
[tex]= 100.765^{\circ} C[/tex]
Thus the above approach is right.
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Related Questions
Ways in which ions may form include
Answers
Answer:
Ions are formed by the addition of electrons to, or the removal of electrons from, neutral atoms or molecules or other ions; by combination of ions with other particles; or by rupture of a covalent bond between two atoms in such a way that both of the electrons of the bond are left in association
The ways Ions may form includes the following
The addition of electrons to neutral atoms or moleculesThe removal of electrons from neutral atoms or molecules By combination of ions with other particlesWhen the number of protons does not equal the number of electrons in an atomMeaning of an IonAn ion can be defined as an atom or group of atoms possessing an electrical charge. Ions are of two types, they are : Anions which are negatively charged and Cations which are positively charged.
In conclusion, an ion can be formed by many ways, but a few has been listed above.
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Can someone help me with this
Answers
Answer:
wow!
5. C
6. B
7. B
8. A
Explanation:
Which two continents does the map show as having the most earthquakes?
Answers
Answer:
Where is the map?
Explanation:
Answer:
On the map, Central and South Asia emerge as the areas of the world where earthquakes are more likely to strike, and with greater intensity.
Explanation:
this means that Asia is the most garenteed to get earthquakes rather than many other places
hope this helps
i need all these im not in the mood for it toddayyy
Answers
Answer:
Me too
Explanation:
(i) The yield of lead iodide from this experiment was 3.5 g.
The theoretical yield of lead iodide for this experiment was 5.0 g.
Calculate the percentage yield of lead iodide in this experiment.
Answers
Answer:
Explanation:
48833.03
Calculate the bond energy in the ionic compound Nacl if the bond length is 2.36x10^-10m
Answers
This question is incomplete, the complete complete question is;
Coulomb's law for the energy of interaction between two charged ions;
E = Ke × q1q2/r
Coulomb's constant Ke = 2.31 × 10⁻²⁸ J.m.
Calculate the bond energy in the ionic compound NaCl if the bond length is 2.36 × 10⁻¹⁰m
Answer:
the bond energy is -9.788 × 10⁻¹⁹ J
Explanation:
Given the data in the question;
Ke = 2.31 × 10⁻²⁸ J.m which is the same as; Ke = 2.31 × 10⁻²⁸ Nm L/c²
ionic compound NaCl;
q1 = charge on Na in NaCl = Na⁺ = + 1C
q2 = charge on Cl in NaCl = Cl⁻ = - 1C
given that bond length r is 2.36 × 10⁻¹⁰m
E = Ke × q1q2/r
we substitute
E = 2.31 × 10⁻²⁸ × (+1 × -1) / 2.36 × 10⁻¹⁰
E = -2.31 × 10⁻²⁸ / 2.36 × 10⁻¹⁰
E = -9.788 × 10⁻¹⁹ J { The negative sign means Attraction in ions }
Therefore, the bond energy is -9.788 × 10⁻¹⁹ J
According to the Bohr model of the atom, which particles are allowed to exist in any one of a number of energy levels?
Answers
Answer: the line-emission spectrum of an atom is caused by the energies released when electrons. releases energy of only certain values.
(i) sodium
(ii) magnesium oxide
(iii) ammonia
Draw a mechanism for the reaction of methanol with sodium amide. In the box to the left, draw any necessary curved arrows. Show the products of the reaction in the box to the right. Include any nonzero formal charges and all lone pairs of electrons. Finally, check the box to indicate which side of the reaction is favored at equilibrium.
Answers
Answer:
See explanation
Explanation:
When sodamide reacts with methanol, the following equilibrium is set up;
CH3OH(aq) + NH2-(aq) ⇄ CH3O-(aq) + NH3(aq)
In the reaction, the sodamide acts as a base that abstracts a proton from methanol to yield the conjugate base of methanol which is the methoxide ion.
The forward reaction is favoured at equilibrium.
Choose the true statement(s) about ions.
a. Anions result when atoms gain an electron.
b. Cations have more protons than electrons.
c. Ions are atoms that have gained or lost neutrons.
d. Na+ has gained 1 proton and therefore has an overall charge of 1.
Answers
Answer: The TRUE statements about an ion includes:
a. Anions result when atoms gain an electron.
b. Cations have more protons than electrons.
Explanation:
The fundamental unit of matter is ATOM, which is the smallest particle of an element that can take part in a chemical reaction. The constituents of the atom are PROTON, NEUTRON and ELECTRONS.
The theory of the possible model of an atom and the position of each constituent within the atom was given by Lord Rutherford. The nucleus of an atom is made up of the protons and neutron while the electron revolves round it. IONS are formed when these atoms either gains or losses these electrons.
When an atom gains electrons to complete it's outermost shell, it acquires a negative charge. This is because the electrons are more than the protons. This type of atom is called an ANION
When an atom losses an electron, it in turn acquires a positive charge. This is because the proton are more than the electrons. This is called the CATION.
Therefore the true statement about ions is option a and b.
Option C is false because it is an electron that is either loss or gained to form an ion not Neurons. Option D is wrong because Na+ lost one electron to become positively charged.
30 points.
Given 450.98 g of Cu(NO3)2, how many moles of Ag can be made? Provide your final answer rounded to two decimal places.
Cu + 2 AgNO3 → Cu(NO3)2 + 2 Ag
Answers
Answer:
The answer is 2.4moles of Ag
Explanation:
450.98g Cu(NO3)2/1 x 1mole/187.554g Cu(NO3)2 = 2.4moles Ag
If energy is conserved will the maximum speed of the pendulum depend on the mass, the length, or both? How?
Answers
Answer:
BUDDY YO
Explanation:
how does a constructive relationship influence your well being
Answers
Answer:
how does a constructive relationship influence your well being
Explanation:
Constructive and deconstructive relationships can influence the well being of different people in different ways. From the point of view who value relationships, dealing with one who repeatedly ruins it is stressful, it slowly damages the health and will continue to do so unless the individual separates himself or herself from the one causing the pain.
please help me with this problem
Answers
the amount of reactants = the amount of products
N2 + 3H2 --> 2NH3
Which of the following is true of cartilage?
absorbs shock
is relatively stretchy
does not attach to bone
is not considered connective tissue
Answers
Answer:
absorbs shock
Explanation:
Answer: absorbs shock
Explanation:
Which of the following would be produced when two or more different atoms bond chemically?
O A. compounds
.
B. elements
C. solutions
D. mixtures
Answers
Answer:
When two or more atoms chemically bond with each other, the resultant chemical structure is a molecule. The familiar water molecule, H2O, consists of two hydrogen atoms and one oxygen atom; these bond together to form water, irdk but it's either C or D
Explanation:
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Convert 3.01 x 10^24 molecules of ammonium sulfate to mass
Answers
Mass of ammonium sulfate = 660.7 g
Further explanationGiven
3.01 x 10²⁴ molecules of ammonium sulfate
Required
mass
Solution
The mole is the number of particles(molecules, atoms, ions) contained in a substance
1 mol = 6.02.10²³ particles
Can be formulated
N=n x No
N = number of particles
n = mol
No = Avogadro's = 6.02.10²³
mol ammonium sulfate (NH₄)₂SO₄ :
n = N : No
n = 3.01 x 10²⁴ : 6.02 x 10²³
n = 5
mass ammonium sulfate :
= mol x MW
= 5 x 132,14 g/mol
= 660.7 g
How did American prepare for and fight for the France battle
Answers
Answer:
their warfare had changed dramatically
Answer:
Explanation:
They first tried to build there army. They did this by passing the Selective Service Act. ... In the next 18 months about 4 million men and women joined the army, but then the army had to be educated.
Sam records the mass of his evaporating dish as 6.488 g. He records the mass of the evaporating dish and the sample of hydrate as 19.72 g. After heating the sample in the evaporating dish to constant weight, the mass of them combined is 11.344 g. How many moles of water were removed from the sample by the heating process?
Answers
Answer:
[tex]0.46[/tex] moles of water were removed from the sample by the heating process
Explanation:
Given
Mass of the evaporating dish [tex]= 6.488[/tex] grams
Mass of the sample of hydrate [tex]= 19.72[/tex] grams
Mass of the sample and dish after heating [tex]= 11.344[/tex] grams
The weight of water removed through evaporation
[tex]= 19.72 - 11.344 = 8.376[/tex] grams
Weight of one mole of water [tex]= 18[/tex] grams
Number of moles of water in [tex]8.376[/tex] Grams of water is equal to
[tex]\frac{8.376}{18} = 0.46[/tex] moles
A molecule that contains three identical polar bonds to the central atom will be?
Answers
The question is incomplete, the complete question is;
A molecule that contains three identical polar bonds to the central atom will be ________.
nonpolar if the geometry is planar triangular
polar in all cases
nonpolar in all cases
impossible to tell the polarity
either polar or nonpolar depending on the identity of the atoms bonded to the central atom
Answer:
Nonpolar if the geometry is planar triangular
Explanation:
The polarity of molecules depends both on the polarity of individual bonds in the molecule as well as the overall dipole moment of the molecule. We must remember that dipole moment is a vector quantity hence direction of the resultant vector is very important.
Now, if i have a molecule that contains three identical polar bonds, a planar triangular geometry means that the molecule is symmetrical and will have an overall dipole moment of zero. Hence the molecule is nonpolar.
Help help help help help
Answers
Sedimentary rocks forms by layers of sediment that dries together.
Metamorphic rocks forms by existing rocks that are exposed to extreme conditions.
2. Describe briefly of some ways these organisms might interact with
each other. (5 points)
Answers
A 10.11 g sample of NaBr contains 22.34 % Na by mass. Considering the law of constant composition (definite proportions), how many grams of sodium does a 7.09 g sample of sodium bromide contain
Answers
Answer:
[tex]1.58\ \text{g}[/tex]
Explanation:
10.11 g sample of [tex]NaBr[/tex] contains 22.34% [tex]Na[/tex] by mass
According to the law of constant composition the if one sample of [tex]NaBr[/tex] has 22.34% of [tex]Na[/tex] by mass then any other sample of [tex]NaBr[/tex] will have the same percentage of the amount of [tex]Na[/tex].
For a sample of 7.09 g we have
[tex]7.09\times \dfrac{22.34}{100}=1.583906\approx 1.58\ \text{g}[/tex]
The mass of sodium in the required sample is [tex]1.58\ \text{g}[/tex].
Adding 1.56 g of K2SO4 to 6.00 mL of water at 16.2ºC causes the temperature of the solution to drop by 7.70ºC.
How many grams of NaOH (ΔHsoln = –44.3 kJ/mol) would you need to add to raise the temperature back to 16.2ºC?
Answers
Answer:
You need to add 0.243g of NaOH to raise the temperature back to 16.2°C
Explanation:
Using the equation:
Q = C*m*ΔT
Where Q is heat
C is specific heat
m is mass
and ΔT is change in temperature
We can find the heat required to increase the temperature of the solution back to 16.2°C:
Assuming specific heat of the solution of water + K2SO4 = Specific heat of water:
C = 4.184J/g°C
m = 1.56g + 6.00g = 7.56g
ΔT = 16.2°C - 7.70°C = 8.50°C
Q = 4.184J/g°C * 7.56g * 8.50°C
Q = 268.86J = 0.269kJ of heat are required
As this heat is obtained from the dissolution of NaOH:
0.269kJ * (1mol NaOH / 44.3kJ) = 0.00607 moles of NaOH are required
In grams -Molar mass NaOH: 40g/mol-:
0.00607 moles NaOH * (40g / mol) =
You need to add 0.243g of NaOH to raise the temperature back to 16.2°CWhich one of the following statements best describes electronegativity in atoms?
A) Electronegativity is what happens when an atom gains an electron to become an anion.
B) Electronegativity is the attraction an element's nucleus has for the electrons in a chemical bond
C) Electronegativity is the energy lost when an atom gains an electron
D) Electronegativity is the energy absorbed when an atom loses an electron
Answers
Answer: B) Electronegativity is the attraction an element's nucleus has for the electrons in a chemical bond
Explanation:
Electronegativity is defined as the property of an element to attract a shared pair of electron towards itself.
When the size of an atom decreases as we move across the period, as the electrons get added to the same shell and the nuclear charge keeps on increasing. Thus the electrons get more tightly held by the nucleus.
As, the size of an element decreases, the valence electrons come near to the nucleus. So, the attraction between the nucleus and the shared pair of electrons increases and thus the electronegativity increases.
Calculate the [H+]
and pH of a 0.000295 M
butanoic acid solution. Keep in mind that the a
of butanoic acid is 1.52×10−5
Answers
[H⁺]=6.696 x 10⁻⁵
pH = 4.174
Further explanationGiven
The concentration of 0.000295 M (2.95 x 10⁻⁴ M) butanoic acid solution
Required
the [H+] and pH
Solution
Butanoic acid is the carboxylic acid group. Carboxylic acids are weak acids
For weak acid :
[tex]\tt [H^+]=\sqrt{Ka.M}[/tex]
Input the value :
[H⁺]=√1.52 x 10⁻⁵ x 2.95 x 10⁻⁴
[H⁺]=6.696 x 10⁻⁵
pH = - log [H⁺]
pH = - log 6.696 x 10⁻⁵
pH = 5 - log 6.696
pH = 4.174
PLEASE ANSWER QUICKLY!!!
Answers
Answer:
A and C
Explanation:
An ion dipole interaction exists between a molecule having a dipole and an ion. The positive end of the dipole interacts with a negative ion while the negative end of the dipole interacts with a positive ion.
If we look at the options listed, the H-H bond is non polar, hence it can not show ion-dipole interaction.
Similarly, the H-F bond is polar, but the negative end of the dipole (F) is made to interact with a sulphide(negative) ion which is incorrect.
Gold has a density of 19.3 g/cm'. Find the volume, in cubic
centimeters, of a sample of gold that weighs 0.715 kg.
Answers
Answer:
37.05 cm³
Explanation:
0.715 kg = (0.715 × 1000) g = 715g
volume = mass/density = 715/19.3 = 37.05 cm³
Strontium metal reacts with aluminum chlorate to produce strontium
chlorate and aluminum metal. Identify the type of reaction, then write a
complete balanced chemical equation for the reaction. If no reaction
occurs, explain why. (2 points)
Answers
Answer: single replacement reaction, [tex]3Sr+2Al(ClO_3)_3\rightarrow 3Sr(ClO_3)_2+2Al[/tex]
Explanation:
A single replacement reaction is one in which a more reactive element displaces a less reactive element from its salt solution.
A general single displacement reaction can be represented as :
[tex]XY+Z\rightarrow XZ+Y[/tex]
As strontium metal is added to aluminum chlorate , strontium being more reactive than aluminium, displaces aluminium atom its salt solution and lead to formation of strontium chlorate and aluminum metal.
[tex]3Sr+2Al(ClO_3)_3\rightarrow 3Sr(ClO_3)_2+2Al[/tex]
Which of the following substances contains MOSTLY ionic bonding? A) LIF B) CO2 C) AICI: D) BeCl2 E) Cu
Answers
Answer: [tex]LiF[/tex] , [tex]AlCl_3[/tex] and [tex]BeCl_2[/tex]
Explanation:
An ionic bond is formed when an element completely transfers its valence electron to another element. The element which donates the electron is known as electropositive element or the metal and the element which accepts the electrons is known as electronegative element or non metal.
A covalent bond is formed when an element shares its valence electron with another element. This bond is formed between two non metals.
[tex]LiF[/tex] , [tex]AlCl_3[/tex] and [tex]BeCl_2[/tex] contain ionic bonds as they aremade up of metals and non metals.
The main purpose of the muscular system is to ____
A. Lift heavy things
B. Allow for movement
C Allow for structure
D. Rid the body of unwanted waste
Answers
Answer: B. Allow for movement
Explanation: Because the muscular system is composed of specialized cells called muscle fibers. Their predominant function is contractibility. Muscles, attached to bones or internal organs and blood vessels, are responsible for movement. Nearly all movement in the body is the result of muscle contraction. Make sure to add me as a friend!!! <3 YW!!!