Answer:
Approximately [tex]4.92[/tex].
Explanation:
Initial volume of the solution: [tex]V = 190.0\; \rm mL = 0.1900\; \rm L[/tex].
Initial quantity of [tex]\rm NH_3[/tex]:
[tex]\begin{aligned} n({\rm NH_3}) &= c({\rm NH_3}) \cdot V({\rm NH_3}) \\ &= 0.3733\; \rm mol \cdot L^{-1} \times 0.1900\; \rm L \\ &\approx 0.154375\; \rm mol\end{aligned}[/tex].
Ammonia [tex]\rm NH_3[/tex] reacts with hydrochloric [tex]\rm HCl[/tex] acid at a one-to-one ratio:
[tex]\rm NH_3 + HCl \to NH_4 Cl[/tex].
Hence, approximately [tex]n({\rm HCl}) = 0.154375\; \rm mol[/tex] of [tex]\rm HCl\![/tex] molecules would be required to exactly react with the [tex]\rm NH_3\![/tex] in the original solution and hence reach the equivalence point of this titration.
Calculate the volume of that [tex]0.3733\; \rm mol \cdot L^{-1}[/tex] [tex]\rm HCl[/tex] solution required for reaching the equivalence point of this titration:
[tex]\begin{aligned}V({\rm HCl}) &= \frac{n({\rm HCl})}{c({\rm HCl})} \\ &\approx \frac{0.154375\; \rm mol}{0.3733\; \rm mol \cdot L^{-1}} \approx 0.413541\; \rm L\end{aligned}[/tex].
Hence, by the assumption stated in the question, the volume of the solution at the equivalence point would be approximately [tex]0.413541\; \rm L + 0.1900\; \rm L \approx 0.6035\; \rm L[/tex].
If no hydrolysis took place, [tex]0.154375\; \rm mol[/tex] of [tex]\rm NH_4 Cl[/tex] would be produced. Because [tex]\rm NH_4 Cl\![/tex] is a soluble salt, the solution would contain [tex]0.154375\; \rm mol\![/tex] of [tex]\rm {NH_4}^{+}[/tex] ions. The concentration of [tex]\rm {NH_4}^{+}\![/tex] would be approximately:
[tex]\begin{aligned}c({\rm {NH_4}^{+}}) &= \frac{n({\rm {NH_4}^{+}})}{V({\rm {NH_4}^{+}})}\\ &\approx \frac{0.154375\; \rm mol}{0.6035\; \rm L} \approx 0.255782\; \rm mol \cdot L^{-1}\end{aligned}[/tex].
However, because [tex]\rm NH_3 \cdot H_2O[/tex] is a weak base, its conjugate [tex]\rm {NH_4}^{+}[/tex] would be a weak base.
[tex]\begin{aligned}pK_{\rm a}({{\rm NH_4}}^{+}) &= pK_{\rm w} - pK_{\rm b}({\rm NH_3})\\ &\approx 13.99 - 4.75 = 9.25\end{aligned}[/tex].
Hence, the following reversible reaction would be take place in the solution at the equivalence point:
[tex]\rm {NH_4}^{+} \rightleftharpoons NH_3 + H^{+}[/tex].
Let [tex]x\; \rm mol \cdot L^{-1}[/tex] be the increase in the concentration of [tex]\rm H^{+}[/tex] in this solution because of this reversible reaction. (Notice that [tex]x \ge 0[/tex].) Construct the following [tex]\text{RICE}[/tex] table:
[tex]\begin{array}{c|ccccc} \textbf{R}& \rm {\rm NH_4}^{+} & \rightleftharpoons & {\rm NH_3}& + & {\rm H}^{+}\\ \textbf{I} & 0.255782 \; \rm M \\ \textbf{C} & -x \;\rm M & & + x\;\rm M & & + x\; \rm M \\ \textbf{E} & (0.255782 - x)\; \rm M & & x\; \rm M & & x\; \rm M\end{array}[/tex].
Thus, at equilibrium:
Concentration of the weak acid: [tex][{\rm {NH_4}^{+}}] \approx (0.255782 - x) \; \rm M[/tex].Concentration of the conjugate of the weak acid: [tex][{\rm NH_3}] = x\; \rm M[/tex].Concentration of [tex]\rm H^{+}[/tex]: [tex][{\rm {H}^{+}}] \approx x\; \rm M[/tex].[tex]\displaystyle \frac{[{\rm NH_3}] \cdot [{\rm H^{+}}]}{[{ \rm {NH_4}^{+}}]} = 10^{pK_\text{a}({\rm {NH_4}^{+}})}[/tex].
[tex]\displaystyle \frac{x^2}{0.255782 - x} \approx 10^{-9.25}[/tex]
Solve for [tex]x[/tex]. (Notice that the value of [tex]x\![/tex] is likely to be much smaller than [tex]0.255782[/tex]. Hence, the denominator on the left-hand side [tex](0.255782 - x) \approx 0.255782[/tex].)
[tex]x \approx 1.19929 \times 10^{-5}[/tex].
Hence, the concentration of [tex]\rm H^{+}[/tex] at the equivalence point of this titration would be approximately [tex]1.19929 \times 10^{-5}\; \rm M[/tex].
Hence, the [tex]pH[/tex] at the equivalence point of this titration would be:
[tex]\begin{aligned}pH &= -\log_{10}[{\rm {H}^{+}}] \\ &\approx -\log_{10} \left(1.19929 \times 10^{-5}\right) \approx 4.92\end{aligned}[/tex].
how many elements are in 2o2
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.
Look at sample problem 19.5 in the 8th ed Silberberg book. Write the ion-product expression at equilibrium for each compound: How to enter the correct answer: e.g. silver sulfate (Ag2SO4) enter this: {Ag+}2{SO42-} don't enter spaces, use square brackets [] not{}or () for concentration and don't worry about subscripting or superscripting
(1) magnesium carbonate
(2) calcium phosphate
(3) silver sulfide
Answer:
See explanation
Explanation:
The term ion product is an expression that does not necessarily reflect equilibrium conditions which can be used to determine the concentration of ions in a solution of the stated substance. As a matter of fact, the ion product is different from the solubility product which reflects equilibrium conditions.
The ion product of the following substances are shown below;
magnesium carbonate - MgCO3
MgCO3(aq) -------> [Mg^2+] [CO3^2-]
calcium phosphate - Ca3(PO4)2
Ca3(PO4)2(aq) --------> [Ca^2+]^3 [PO4^3-]^2
silver sulfide - Ag2S
Ag2S(aq) --------> [Ag^+]^2 [S^2-]
The freezing point of pure water is 0.0°C. How many grams of ethylene glycol (C2H6O2) must be mixed in 100.0 g of water to lower the freezing point of the solution to -8.8°C? g
Answer:
17.54 g
Explanation:
the freezing point of the solution to -8.8°C
depression in freezing point = 8.8°C
Molal freezing point depression constant of ethylene glycol Kf = 3.11⁰C /m
ΔTf = Kf x m , m is no of moles of solute per kg of solvent .
Let gram of ethylene glycol required be x .
moles = m / mol weight of ethylene glycol
= x / 62
100 g of water = .1 kg
moles of solute dissolved in 1 kg of water
m = x / 62 x .1
m = 10 x / 62
Using the above equation for depression in freezing point
8.8 = 3.11 x 10 x / 62
x = 17.54 g .
The mass of ethylene glycol required to lower the freezing point is 17.54 g.
The given parameters:
Freezing point of a pure water, = 0⁰CMass of water, m = 100 gFreezing point of the solution, = -8.8⁰CMolar freezing point depression constant of ethylene glycol Kf = 3.11⁰C /m
Let the mass of ethylene glycol required be x .
The number of moles of the ethylene is calculated as follows;
[tex]n = \frac{x}{M} \\\\n = \frac{x}{62 \times 100 g \ of H_2 O}\\\\n = \frac{x}{6.2}[/tex]
Apply the following equation for depression in freezing point as follows;
[tex]\Delta T_f = n Kf\\\\8.8 = 3.11 \times \frac{x}{6.2} \\\\3.11 x = 54.56\\\\x = \frac{54.56}{3.11} \\\\x = 17.54 \ g[/tex]
Thus, the mass of ethylene glycol required to lower the freezing point is 17.54 g.
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what is the fundamental building unit
Answer:
The basic building blocks that make up matter are called atoms.
I hope it's helpful!
All camels are basically similar in structure. They have developed adaptations for
coping with both heat and dehydration.
Which of the following does not benefit the camel as a means of preventing dehydration?
A. Camels can extract water from their solid wastes.
B. Camels’ ears are lined with fur to keep out sand and other blowing matter.
C. Their kidneys are capable of concentrating urine to reduce water loss.
D. Camels are able to locate water in any environment.
Answer:
B. Camels’ ears are lined with fur to keep out sand and other blowing matter.
What is the surface composition of planets in the solar system?
A,. Helium or hydrogen
B,. Rock or gas
C., Rock or water
D,. Water or helium
Answer:
B
Explanation:
Most planets in the solar system don't have water. Helium and hydrogen are two of the many gasses in planets. Therefore, B is the best answer.
Which elements make up 95 percent (by weight) of the human body?
Question 1
Which of the following types of electromagnetic radiation has the shortest wavelengths?
A. Infrared
B. Ultraviolet
C. Visible light
D. Radio waves
Electromagnetic radiation is the energy waves with various wavelengths. Ultraviolet rays have the shortest wavelength. Thus, option B is correct.
What is wavelength?A wavelength is a ratio of the velocity and the frequency as the distance between the crests is measured. The shortest wavelength haves the largest frequency.
Radio waves have the longest wavelength but the shortest frequency and similarly the gamma rays have the shortest wavelength. Ultraviolet rays come before the X-rays and the gamma rays have a short wavelength.
Therefore, option B. UV rays have the shortest wavelength.
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Which of the following occurs when glaciers melt?
Answer Choices
1. rising
2. sea levels
3. falling sea levels
4. earthquakes
5. tsunamis
Answer
5.tsunamis
Explanation:
Answer:
OMG i did a whole report about this a very long time ago but the answer is the sea level rises lol
Explanation:
hope this helps :) have a nice day!
What is the surface composition of planets in the solar system?
A,. Helium or hydrogen
B,. Rock or gas
C., Rock or water
D,. Water or helium
Answer:
A: Helium or Hydrogen
Explanation:
Terrestrial planets are the 4 inner most planets of the solar system which are mercury, venus, earth, Mars, while the giant planets are the 4 outer most which are Jupiter, Saturn, Uranus and Neptune.
Now, these outer most ones are the surface ones and are surrounded primarily by layers of hydrogen and helium gases.
A certain liquid X has a normal boiling point of 129.90°C and a boiling point elevation constant =Kb= 1.67°C·kgmol^−1. Calculate the boiling point of a solution made of 90.g of iron(III) chloride (FeCl3) dissolved in 650.g of X.
Answer:
Boiling T° of solution = 135.6°C
Explanation:
Formula for elevation boiling point is:
ΔT = Kb . m . i
ΔT = Boiling point of solution - Boiling point of pure solvent
Kb = Boiling point elevation constant
m = molality → moles of solute in 1kg of solvent
i = numbers of ions dissolved
FeCl₃ → Fe³⁺ + 3Cl⁻
In the dissociation of the ionic salt, we determined 4 moles of ions dissolved.
3 for chlorides and 1 for iron. Then i = 4
m → We convert the mass of solute to moles:
90 g . 1mol / 162.2g = 0.555 moles
650 g of solvent = 0.650 kg of solvent
m = 0.555 mol/0.650kg → 0.85
We replace data at formula
Boiling T° of solution - 129.90°C = 1.67°C . kg/mol . 0.85 mol/kg . 4
Boiling T° of solution = 1.67°C . kg/mol . 0.85 mol/kg . 4 + 129.90°C
Boiling T° of solution = 135.6°C
Every orbital in a sub level is singly occupied before any orbital is doubly occupied is the statement of
Answer:
Hund's rule of maximum multiplicity
Attempt 2
Four marbles are made of different metals. Each marble has the same mass, but a different volume. The density of each
metal is given in the table.
Metal
Density (g/mL)
aluminum
2.70
silver
10.5
rhenium
20.8
nickel
8.90
Place the marbles in order from largest to smallest.
Largest
The order of marbles can be Aluminum, Nickel, Silver, and Rhenium.
What is volume?If volume is the amount of three-dimensional space contained by a closed surface, such as the amount of space within a given cube, cylinder, or other three-dimensional shape.
Liquid volume is a way to measure an amount of liquid by describing how much three-dimensional space it occupies.
The mass of something is the amount of stuff it is made of. The volume of an object is the amount of space it usually takes up.
Density provides an easy way to calculate a body's mass from its volume or vice versa.
The mass is equal to the volume multiplied by the density (M = Vd), and the volume is equal to the mass divided by the density (V = M/d).
As per the density given, the volume of aluminum can be 1.11mL, Silver is 0.286mL, Rhenium is 0.144mL, Nickel is 0.337mL.
Thus, the order from largest to smallest will be Aluminum, Nickel, Silver, and Rhenium.
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What are two ways to determine the salinity level?
Answer: chlorinity titration and conductometry
Explanation:
Describe how naturally
acidic rainwater can affect a
mountain of limestone.
Answer:
The naturally acidic rain will gradually wear the mountain of limestone away.
Hope it helps!
Jane is sitting in the family car. Her mother is driving her from their house to the library. Jane waves as she passes her friend Marina. Which of the following is not moving with respect to Jane?
A. Marina
B. The family car
C.The library
D. Jane’s house
Answer:
B) The family car
Explanation:
I hope this helps :)
which question is the student most likely trying to answer?
Answer:
B in my opinion
Explanation:
Answer:
I would say A. perhaps B but I'm leaning towards a.
Which food dyes in the diagram on the right only contain one colour?
( Science, Chromatography )
is C2Br2 ionic or covalent
Which statement best describes the coriolis effect
The coriolis effect is responsible for many large scale weather patterns. The coriolis force is responsible for the deflection of objects. It is this effect which drive the global wind and ocean circulation patterns. The correct option is C.
What is coriolis effect?The apparent effect produced by a rotating frame of reference is defined as the coriolis effect. This effect occurs when an object moving along a straight path is viewed from a non-fixed frame of reference.
Because of the earth's rotation, when an object moving in a straight path is viewed from earth, it appears to lose its course. So the travelling long distances around the earth appear to move at a curve instead of a straight line due to coriolis effect.
The coriolis effect is found to be strongest near poles and it is absent at the equator. The coriolis force is an apparent force caused by the rotation of earth.
Thus the correct option is C.
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Your question is incomplete, most probably your question was:
Which statement best describes the coriolis effect
A. The oceans that receive more rain have water with lower salinity.
B. Closer to the poles, the temperature of ocean water decreases.
C. The rotation of Earth causes the apparent path of ocean currents
to curve,
D. Ocean water becomes denser the deeper you go underwater.
The specific gravity of crude oil is 0.876. If 1.00 liter of water weighs 1.00 kilograms, what is the weight of a liter of crude oil ( show work)
0.876 kg or 1.14kg
I need to know this too. Hopefully someone answers quick lol
The specific gravity of crude oil is 0.876 as 1.00 liter of water weighs 1.00 kilograms. Then weight of crude oil is 0.876 kg.
What is specific gravity?A specific gravity is a dimensionless quantity and it is defined as the ratio of density of substance to the density of water.
It is used to determine where the object will float on the surface of liquid approximately.
As, density = mass / volume
Volume of water is 1 ml given.
So, density of substance = mass of substance
Specific gravity = density of substance / density of water
So, Specific gravity = mass of substance / density of water
Mass of substance = specific gravity x density of water
= 0.876 x 1.00 kg = 0.876 kg
Thus, the specific gravity of crude oil is 0.876 as 1.00 liter of water weighs 1.00 kilograms. Then weight of crude oil is 0.876 kg.
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In the lab activity, the reaction rate was determined by the appearance of a product. However, the reaction rate can also be determined by the disappearance of a reactant. Rate =Δ[product]/Δt or rate−Δ[reactant]Δt. In each situation below, you are given a rate measured by the appearance of one component of the reaction and are asked to predict the rate of appearance or disappearance of another component, based on logic and stoichiometric relationships.
For example, if the reaction is as follows:
A+2B⟶products
For every mole of A that is used, 2 moles of B are used so the rate of disappearance of B is twice the rate of the disappearance of A.
This may be expressed as:
rate=−Δ[B]/Δt=−2[A]/Δt , N2(g)+3H2(g)⟶2NH3(g)
The reaction rate is measured as 0.032 M NH3/s. Determine the rate of disappearance of N2 and the rate of disappearance of H2. Explain how you arrived at your answers.
Answer: Rate of disappearance of [tex]N_2[/tex]= 0.032 M/s
Rate of disappearance of [tex]H_2[/tex] = 0.096 M/s
Explanation:
Rate law says that rate of a reaction is directly proportional to the concentration of the reactants each raised to a stoichiometric coefficient determined experimentally called as order.
[tex]N_2(g)+3H_2(g)\rightarrow 2NH_3(g)[/tex]
The rate in terms of reactants is given as negative as the concentration of reactants is decreasing with time whereas the rate in terms of products is given as positive as the concentration of products is increasing with time.
Rate in terms of disappearance of [tex]N_2[/tex] = [tex]-\frac{1d[N_2]}{dt}[/tex]
Rate in terms of disappearance of [tex]H_2[/tex] = [tex]-\frac{1d[H_2]}{3dt}[/tex]
Rate in terms of appearance of [tex]NH_3[/tex] = [tex]\frac{1d[NH_3]}{2dt}[/tex]
Rate = [tex]-\frac{1d[N_2]}{dt}=-\frac{1d[H_2]}{3dt}=\frac{1d[NH_3]}{2dt}[/tex]
Given : = 0.032 M/s
Rate of disappearance of =
Rate of disappearance of [tex]H_2[/tex] = [tex]-\frac{d[H_2]}{dt}=3\times 0.032M/s=0.096M/s[/tex]
Empirical formula for S3O9
Answer:
* The empirical formula of a compound shows the ratio of elements present in a compound
* The molecular formula of a compound shows how many atoms of each element are present in a molecule of a compound.
Example: the compound butene has a molecular formula of C4H8. The empirical formula
of butene is CH2 because there is a 1:2 ratio of carbon atoms to hydrogen atoms.
1 mole = _____________________ _________________ particles
1 mole = 6.02 * 10^23 atoms
This is known as Avogadro's Number. This value is approximate.
Answer:
6.022×10^23
Explanation:
6.022×10^23 is known as avagadro's number or avagadro's constant
qualitative test for formaldehyde
Answer:
The rapid qualitative analysis method comprises that a Schiff reagent and a strong acid solution with a certain concentration are prepared, a sample and the Schiff reagent undergo a reaction, a strong acid solution is added into the reaction product and formaldehyde in the sample can be detected according to solution
Explanation:
:)
The less dense the air is, the less
and other gases are available for respiration
H.w. balance the following equations:
a) Iron + chlorine → Iron (iii) chloride
b) Nitrogen + hydrogen → Ammonia
c) Phosphoric acid + sodium carbonate → sodium phosphate + water + carbon dioxide
d) Nitrogen dioxide + water + oxygen → Nitric acid
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
The level of a liquid (i.e. distilled water) in laboratory glassware is determined by sight. The level corresponds to a specific volume. The volume is established by identifying the meniscus of the liquid relative to a calibration mark or series of calibration marks on the glassware (ie. volumetric flask vs. buret). Which of the following statements is NOT correct when reading the meniscus?
a. The edge of the meniscus should be used to determine volume relative to the mark or marks
b. The meniscus should be read at eye level
c. When the meniscus is between marks, estimate the reading to the nearest tenth of a division (ie, estimate to 0.01 mL if buret has 0.1 ml divisions)
d. The center of the meniscus should be used to determine volume relative to the mark or marks
Answer:
c. When the meniscus is between marks, estimate the reading to the nearest tenth of a division (ie, estimate to 0.01 mL if buret has 0.1 ml divisions)
Explanation:
The meniscus is the mark that a liquid presents in a pipette. This measure is important for determining the volume of a solution, allowing the correct amounts of aqueous solutions to be used. The meniscus must be observed at eye level to avoid parallax errors. In this view, the border and center of the meniscus must be considered to determine the volume.
The temperature of an oxyacetylene torch flame can reach as high as 3137 °C. What is this temperature in Fahrenheit and Kelvin? Please show work.
Answer:
A)3410K
B)5678.6 °F
Explanation:
✓ To convert Celcius to Kelvin expression below can be used
K= °C + 273
We were given T=3137 °C
= 3137 + 273= 3410K
✓To convert Celcius to Fahrenheit, expression below can be used
°F =(°C × 9/5) + 32
We were given T=3137 °C
°F= (3137 × 9/5) + 32
= 5646.6+32
=5678.6 °F
Compare the cycling of water and nutrients through an ecosystem to the cycling of blood in your cardiovascular system. What is the source of energy in each case?
The cycling of water and nutrients through an ecosystem is powered mainly by the sun, while the cycling of blood in the cardiovascular system "powered" by the heart.
Hope this helps!
The ecosystem has been the correlation between the biotic and abiotic components in the specified area.
The cardiovascular system has been the organ system comprising heart, arteries and veins. It functions to carry blood.
Cycling of water, nutrients, and bloodThe water and nutrients in the ecosystem are absorbed and converted to another form and return to the original form. This has been known as the cycle of the water.
The water in the stream and ocean has been converted to the vapor form. It has been evaporated by the energy of sun.
The evaporated vapors have been converted to the clouds by condensation, and the precipitation results in the poring of water again to the stream and ocean.
The circulation in the body has been mediated in the same way as the water cycle. The blood has been pumped from the heart.
The veins carry the blood to different tissues and cells. It has been used, and carried back from the cells to the heart.
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