Answer:
Hydrogen peroxide is ans
A growing concern in agricultural and food chemistry is the presence of residues in food. We use many forms of organic chemicals in agriculture and food chemistry and there is growing concern as to how safe these materials are. Choose an organic chemical used in agricultural of food chemistry and report on the functional groups contained in your compound, the uses of the compound, and the safety of that compound.
Answer:
Monosodium Glutamate (MSG) is a chemical which is used in agricultural of food chemistry.
Explanation:
Monosodium Glutamate (MSG) is a chemical that is used in types of different food as food additives. The functional group that is present in Glutamate are carboxylic acid and amine. This chemical is used in different types of foods which is responsible for enhancing the taste of the food. Monosodium Glutamate is safe if it is used in moderate dose but adversely affected when it is used in large amount.
Determine the limiting reactant in a mixture containing 95.7 g of B2O3, 75.7 g of C, and 369 g of Cl2. Calculate the maximum mass (in grams) of boron trichloride, BCl3, that can be produced in the reaction. The limiting reactant is:
Answer:
[tex]B_2O_3[/tex]
Explanation:
First, we have to find the reaction:
[tex]B_2O_3~+~C~+~Cl_2~->~BCl_3~+~CO[/tex]
The next step is to balance the reaction:
[tex]B_2O_3~+~3C~+~3Cl_2~->~2BCl_3~+~3CO[/tex]
Now, we have to calculate the molar mass for each compound, so:
[tex]B_2O_3=~69.62~g/mol[/tex]
[tex]C=~12~g/mol[/tex]
[tex]Cl_2=~70.96~g/mol[/tex]
With these values, we can calculate the moles of each compound:
[tex]95.7~g~B_2O_3\frac{1~mol~B_2O_3}{69.62~g~B_2O_3}=1.37~mol~B_2O_3[/tex]
[tex]75.7~g~C\frac{1~mol~C}{112~g~C}=6.30~mol~C[/tex]
[tex]369~g~Cl_2\frac{1~mol~Cl_2}{70.96~g~C}=5.20~mol~Cl_2[/tex]
Now we can divide by the coefficient of each compound in the balanced equation:
[tex]\frac{1.37~mol~B_2O_3}{1}=~1.37[/tex]
[tex]\frac{6.30~mol~C}{3}=~2.1[/tex]
[tex]\frac{5.20~mol~Cl_2}{3}=~1.73[/tex]
The smallest values are for [tex]B_2O_3[/tex], so this is our limiting reagent.
I hope it heps!
ions always have the same electronic structure as elements in which group of the periodic table?
Answer:
In 0 group of the periodic table
Explanation:
So they will not react with other atoms because they have a full outer shell of electrons and an overall charge of 0.
Hope it helps.
Which of these statements gives a correct reason as to why our body needs water?
(1 Point)
1. It provides us with energy.
2. It helps us to eliminate waste.
3. It helps regulate our body temperature.
Answer:
2. It helps us to eliminate waste
3. It helps regulate our body temperature
Explanation:
In addition to the function of bringing nutrients to the cells, water provides the elimination of substances out of the body. This occurs, for example, through urine, which is basically formed by water and toxic or excess substances dissolved.
Water also helps in regulating body temperature. This occurs when the heat becomes exaggerated, sweat is released, which has water in its composition. When in contact with the medium, the sweat evaporates on the surface of the skin, causing the body to cool.
4.The reaction of 0.25 g magnesium with 100.0 mL of 2 M hydrochloric acid (density d = 1.039 g/ml) raises the temperature of the solution from 20.0 °C to 35.0 °C. The specific heat for HCl is 3.98 J/(g.C). Mg(s) + 2HCl(aq) —> MgCl2(aq) + H2(g) Calculate the heat of the reaction. (Use the equation Q = s . m .ΔT where s is the specific heat, m is the mass of solution and ΔT is the change in temperature)
Answer:
[tex]Q=450.14J[/tex]
Explanation:
Hello,
In this case, for the given equation to compute the heat, we should compute the mass of the solution of hydrochloric acid, thus, the first step is to compute its reacting mass:
[tex]m_{HCl}^{reacting}=2\frac{mol}{L}*0.1000L *\frac{36.45g}{1mol}=7.29g[/tex]
Then, we obtain the total mass of the formed solution:
[tex]m=0.25g+7.29g=7.54g[/tex]
In such a way, we can infer that the specific heat of the solution is mainly the specific heat of hydrochloric acid, therefore the heat turns out:
[tex]Q=3.98\frac{J}{g\°C} *7.54g*(35.0\°C-20.0\°C)\\\\Q=450.14J[/tex]
Regards.
When you turn on the air conditioner during a hot summer day the cooler air will sink to the floor, while warmer air rises to the
ceiling
Which type of heat transfer is this an example of?
(A) conduction
(B) convection
(C) radiation
(D)
kinetic
What are extensive properties of Oxygen?
which best describes a mixture.
A it has a single composition and it has a set of characteristics
B it can have different compositions but it has a set of charactaristics that does not change
C it has a single composition but it has a set of characteristics that does change
D it can have different compositions and it has a set of characteristics that does change
Answer:
B) It can have different compositions, but it has a set of characteristics that does not change.
Explanation:
On e d g e n u i t y
I believe the answer is d lmk if im wrong or right
A base has a molarity of 1.5 M with respect to the hydroxyl ion (OH-) concentration. If 7.35 cm³ of this base is taken and diluted to 147 cm³, then what is the concentration of the hydroxyl ion. How many moles of hydroxyl ion are there in the 7.35 cm³? In the 147 cm³?
Answer:
0.077M is the concentration of the hydroxyl ion
Explanation:
If 7.35 cm3 of this base is take and diluted to 147 cm3, then what is the concentration of the hydroxyl ion?
Use the dilution equation:
M1V1 = M2V2
M1 * 147cm³ = 1.5 M * 7.35 cm³
M1 = 1.5 M * 7.35 cm³ / 147 cm³
M1 = 0.077 M
0.077M is the concentration of the hydroxyl ionHow many moles of hydroxyl ion are there in the 7.35 cm3?
1000 cm³ contains 1.5 mol OH- ions
7.35 cm³ contains : 7.35 cm³ / 1000 cm³ *1.5 mol
= 0.011025 mol
Answer correct to 2 significant digits = 0.011 mol OH- ions.2 FONS
How does the electric force between two charged particles change if the
distance between them is increased by a factor of 22
A. It increases by a factor of 4.
B. It increases by a factor of 2.
C. It decreases by a factor of 4
O
D. It decreases by a factor of 2.
SUB
Answer:
C. It decreases by a factor of 4
Explanation:
F1 = kq1*q2/r²
F2 = kq1*q2/(2r)² = kq1*q2/(4r²) = kq1*q2/(r²*4) = F1/4
Draw every stereoisomer for 1-bromo-2-chloro-1,2-difluorocyclopentane. Use wedge-and-dash bonds for the substituent groups, and be sure that they are drawn on the outside of the ring, adjacent to each other. The skeletal structure of one molecule is included to indicate the proper format.
Answer:
Explanation:
The objective here is mainly drawing the diagrams of every stereoisomer for 1-bromo-2-chloro-1,2-difluorocyclopentane.
Stereoisomerism is the difference of the spatial arrangement of atoms in a molecule or a compound with the same molecular formula.
For 1-bromo-2-chloro-1,2-difluorocyclopentane.
We have the stereoisomers as follows:
(1R,2S)-1-bromo-2-chloro-1,2-difluorocyclopentane.
(1S,2R)-1-bromo-2-chloro-1,2-difluorocyclopentane.
(1S,1S)-1-bromo-2-chloro-1,2-difluorocyclopentane.
(1R,1R)-1-bromo-2-chloro-1,2-difluorocyclopentane.
Their diagrams are drawn and shown in the attached file below in the order with which they are listed above.
A solution of pentane and ethanol (CH3CH2OH)that is 50.% pentane by mass is boiling at 57.2°C. The vapor is collected and cooled until it condenses to form a new solution.
Calculate the percent by mass of pentane in the new solution. Here's some data you may need:
normal boiling point density vapor pressure at
57.2°C
pentane 36.°C 0.63gmL 1439.torr
ethanol 78.°C 0.79gmL 326.torr
Be sure your answer has 2 significant digits.
dont round during math only for answer!
Note for advanced students: you may assume the solution and vapor above it are ideal.
Answer:
The correct answer is 81.52 percent.
Explanation:
Based on the given information, the boiling point of pentane is 36 degree C and the boiling point of ethanol is 78 degree C. The density of pentane and ethanol is 0.63 g/ml and 0.79 g/ml. The vapor pressure of pentane at 57.2 degree C is 1439 torr and the vapor pressure of ethanol at 57.2 degree C is 326 torr.
In the given case, 50 percent pentane by mass signifies that mass of pentane is 50 grams. Thus, the mass of ethanol will be 100-50 = 50 grams.
The moles or n can be calculated by using the formula,
n = weight/molecular mass
The molecular mass of pentane is 72.15 g per mol and the molar mass of ethanol is 46.07 g/mol.
The moles of pentane is,
= 50 g/72.15 g/mol = 0.6930 mol
The moles of ethanol is,
= 50 g/46.07 g/mol = 1.0853 mol
The mole fraction of pentane is,
= 0.6930 mol / (0.6930 + 1.0853) mol = 0.3897
The mole fraction of ethanol is,
= 1.0853 mol / (0.6930 + 1.0853) mol = 0.6103
Now the vapor pressure of solution will be,
= pressure of pentane * mole fraction of pentane + pressure of ethanol * mole fraction of ethanol
= (1439 * 0.3897) + (326 * 0.6103)
= 759.736 torr
The vapor pressure of pentane within the solution,
= vapor pressure of pentane * mole fraction of pentane
= 1439 torr * 0.3897
= 560.778 torr
The fraction of pentane is,
= 560.778 / 759.736 = 0.738
Let us assume that the total mole is 1, the mole fraction of pentane is 0.738, so the mole fraction of ethanol will become, 1-0.738 = 0.262
The mass of pentane = 0.738 * 72.15 = 53.2467
The mass of ethanol = 0.262 * 46.07 = 12.07034
The percent by mass of pentane in new solution will be,
Mass% = mass of pentane/Total mass * 100%
= 53.2467/(53.2467 + 12.07034) * 100%
= 53.2467/65.31704 * 100 %
= 81.52 %
A galvanic cell at a temperature of 25.0°C is powered by the following redox reaction:
2MnO4^-(aq)+16H+(aq)+5Pb(s)-->2Mn^2+(aq)+8H2O(l)+5Pb^2+(aq)
Suppose the cell is prepared with 1.87 M MnO−4 and 1.37 M H+ in one half-cell and 3.23 M Mn+2 and 6.62 M Pb+2 in the other. Calculate the cell voltage under these conditions. Round your answer to 3 significant digits.
Answer:
1.63 V
Explanation:
Let us state the reaction equation again for the purpose of clarity;
2MnO4^-(aq)+16H+(aq)+5Pb(s)-->2Mn^2+(aq)+8H2O(l)+5Pb^2+(aq)
The reduction potentials for the two half reaction equations are;
MnO 4 - (aq) + 8H + (aq) + 5e - → Mn2+(aq) + 4H2O(l) Eo=1.51 V
Pb2+(aq) + 2e - → Pb(s) Eo= -0.13 V
E°cell = E°red – E°Ox
E°cell = 1.51 - (-0.13)
E°cell = 1.51 + 0.13
E°cell = 1.64 V
But Q= [Mn^2+]^2 [Pb^2+]^5/[MnO4^-]^2 [H^+]^16
Q= [3.23]^2 [6.62]^5/[1.87]^2 [1.37]^16
Q= 10.43 × 12714.22/3.4969 × 154
Q= 132609.3/538.5226
Q= 246.25
From Nernst equation
E= E° - 0.0592/n log Q
Where n=10
E= 1.64- 0.0592/10 log 246.25
E= 1.64-0.0142
E= 1.63 V
Consider the following reaction where Kc = 1.80×10-2 at 698 K:
2HI(g) → H2(g) + I2(g)
A reaction mixture was found to contain 0.280 moles of HI (g), 2.09×10^-2 moles of H2 (g), and 4.14×10^-2 moles of I2 (g), in a 1.00 liter container.
Required:
a. Is the reaction at equilibrium?
b. What direction must it run in order to reach equilibrium?
c. The reaction
1. must run in the forward direction to reach equilibrium.
2. must run in the reverse direction to reach equilibrium.
3. is at equilibrium.
Answer:
The system is not in equilibrium and the reaction must run in the forward direction to reach equilibrium.
Explanation:
The reaction quotient Qc is a measure of the relative amount of products and reagents present in a reaction at any given time, which is calculated in a reaction that may not yet have reached equilibrium.
For the reversible reaction aA + bB⇔ cC + dD, where a, b, c and d are the stoichiometric coefficients of the balanced equation, Qc is calculated by:
[tex]Qc=\frac{[C]^{c}*[D]^{d} } {[A]^{a}*[B]^{b}}[/tex]
In this case:
[tex]Qc=\frac{[H_{2} ]*[I_{2} ] } {[HI]^{2}}[/tex]
Since molarity is the concentration of a solution expressed in the number of moles dissolved per liter of solution, you have:
[tex][H_{2} ]=\frac{2.09*10^{-2} moles}{1 Liter}[/tex]=2.09*10⁻² [tex]\frac{moles}{liter}[/tex][tex][I_{2} ]=\frac{4.14*10^{-2} moles}{1 Liter}[/tex]=4.14*10⁻² [tex]\frac{moles}{liter}[/tex][tex][I_{2} ]=\frac{0.280 moles}{1 Liter}[/tex]= 0.280 [tex]\frac{moles}{liter}[/tex]So,
[tex]Qc=\frac{2.09*10^{-2} *4.14*10^{-2} } {0.280^{2} }[/tex]
Qc= 0.011
Comparing Qc with Kc allows to find out the status and evolution of the system:
If the reaction quotient is equal to the equilibrium constant, Qc = Kc, the system has reached chemical equilibrium.
If the reaction quotient is greater than the equilibrium constant, Qc> Kc, the system is not in equilibrium. In this case the direct reaction predominates and there will be more product present than what is obtained at equilibrium. Therefore, this product is used to promote the reverse reaction and reach equilibrium. The system will then evolve to the left to increase the reagent concentration.
If the reaction quotient is less than the equilibrium constant, Qc <Kc, the system is not in equilibrium. The concentration of the reagents is higher than it would be at equilibrium, so the direct reaction predominates. Thus, the system will evolve to the right to increase the concentration of products.
Being Qc=0.011 and Kc=1.80⁻²=0.018, then Qc<Kc. The system is not in equilibrium and the reaction must run in the forward direction to reach equilibrium.
In TLC chromatography of plant pigments, why do different pigments travel up the plate at different rates
What allows two or more atoms to be held together?
Answer:
Atoms come together to form molecules because of their electrons. Electrons can join (or bond) atoms together in two main ways. When two atoms share electrons between them, they are locked together (bonded) by that sharing. These are called covalent bonds.
Explanation:
Answer:
Electrons
Explanation:
took the test got 100%
Hot coffee in a mug cools over time and the mug warms up. Which describes the energy in this system? The average kinetic energy of the particles in the mug decreases. The average kinetic energy of the particles in the coffee increases. Thermal energy from the mug is transferred to the coffee. Thermal energy from the coffee is transferred to the mug.
Answer:
d
Explanation:
Answer:
D
Explanation:
Edge 2021
A 5.00-L tank contains helium gas at 1.50 atm. What is the pressure of the gas in mmHg
Answer:
1140 mmHg
Explanation:
1 atmosphere is 760 mmHg, so 1.5 atmospheres is ...
1.5×760 mmHg = 1140 mmHg
Indicate whether the following represents a Chemical or Physical change: Gasoline burns in air
Answer:
Chemical
Explanation:
Whenever "burns" is being used, most of the time it is a chemical change
Answer:
chemical change
Explanation:
it's a chemical change because when gas burn it produces water and carbon dioxide
After recrystallizing an impure sample with isopropanol, you isolate your product by filtration. What solvent do you use to wash your crystals? Room temperature distilled water Room temperature isopropanol Ice cold distilled water Ice cold isopropanol
Answer:
The correct answer is ice cold isopropanol.
Explanation:
Any compound in the initial stage is first dissolved in any suitable solvent and is heated for a certain duration for the process of recrystallization. Afterward, the compound is kept at room temperature so that it gets cooled gradually. In the process, the impurities remain dissolved in the solvent and the pure compound gets separated in the form of a precipitate.
Post all this, the filtration of the pure compound is done and is then washed with the cold solvent, which was initially used to dissolve the compound. Therefore, the appropriate solvent to use in the process is ice-cold isopropanol.
1. Which statement describes the particles of an ideal gas, based on the
kinetic molecular theory?*
O There are attractive forces between the particles.
O The particles move in circular paths.
O The collisions between the particles reduce the total energy of the gas.
О
The volume of the gas particles is negligible compared with the total volume of the
gas.
Answer:the volume of the gas particles is negligible compared with the total volume of the gas.--D
Explanation:
According to the Kinetic Molecular Theory for ideal gases, it states that
--Gases are composed of larges molecules which are in constant random motion in a straight line
--The volume of the gas particles is negligible compared to the total volume in which the gas is contained.
-----The Attractive and repulsive forces between gas molecules is insignificant ie There are no interactive forces.
----The collisions of the particles are perfectly elastic and energyis being transferred between the particles but the total energy remaining constant
From the statements of the kinetic Molecular theory of ideal gases, it can be seen that the statement which describes the particles of an ideal gas is option D which is The volume of the gas particles is negligible compared with the total volume of the gas--- ---This gives the reason why gases can be compressed. Since there are no inter molecular forces between them. The particles of an ideal gas will move at the same random motion resulting to high pressures, compressing the gas and making the volume negligible or insignificant.
Classify the following unbalanced chemical reaction Na3PO4(aq) + FecCl2(aq) = Fe3(PO4)2(s) + NaCl(aq)
1. Acid-Base Reaction
2. Precipitation Reaction
3. Oxidation-Reduction Reaction
4. Combustion Reaction
Answer:
2. Precipitation Reaction
Explanation:
Na3PO4(aq) + FecCl2(aq) = Fe3(PO4)2(s) + NaCl(aq)
Fe3(PO4)2(s) - solid, it means it will precipitate.
It is a precipitation reaction.
What is precipitate give example?A precipitate is a solid that forms out of a solution. A common example is that of the mixing of two clear solutions: (1) silver nitrate (AgNO3) and (2) sodium chloride (NaCl): The reaction is. The precipitate forms because the solid (AgCl) is insoluble in water.
What is precipitate formation?A precipitate is a solid formed in a chemical reaction that is different from either of the reactants. This can occur when solutions containing ionic compounds are mixed and an insoluble product is formed. The identity of the precipitate can often be determined by examining solubility rules.
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Which is true regarding a water molecule?
Answer:
Has many answers, but one is that it consists of small polar v shaped molecules with a molecular formula H20.
Explanation:
Water molecules consists of 2 hydrogen atoms bonded with on oxygen atom. Each molecule is electrically neutral but polar, with the center of positive and negative charges located in different places.
Each hydrogen atom has a nucleus consisting of a single positively-charged proton surrounded by a 'cloud' of a single negatively-charged electron and the oxygen atom has a nucleus consisting of eight positively-charged protons and eight uncharged neutrons surrounded by a 'cloud' of eight negatively-charged electrons.
Hoped this helped!
What is a good title for this chart?
Answer:
pH of the acid
Explanation:
An ethylene glycol solution contains 21.4 g of ethylene glycol (C2H6O2) in 97.6 mL of water.
Required:
a. Determine the freezing point of the solution. Express you answer in degrees Celsius. (Assume a density of 1.00 g/mL for water.)
b. Compute the boiling point of the solution. (Assume a density of 1.00 g/mL for water.)
Answer:
a. TFinal = -6.57°C
b. Tfinal = 101.80°C
Explanation:
When a solute is added to a solvent producing an ideal solution, the freezing point of the solution decreases with regard to pure solvent. Also, boiling point increases with regard to pure solvent.
The formulas are:
Freezing point:
ΔT = Kf×m×i
Where Kf is freezeing point depression constant of water (1.86°C/m), m is molality of solution and i is van't Hoff factor (1 for ethylene glycol).
Boiling point:
ΔT = Kb×m×i
Where K is freezeing point depression constant of water (0.51°C/m), m is molality of solution and i is van't Hoff factor (1 for ethylene glycol).
Moles of 21.4g of ethylene glycol (Molar mass: 62.07g/mol) are:
21.4g C₂H₆O₂ ₓ (1mol / 62.07g) = 0.345 moles
And kg of 97.6mL of water = 97.6g are 0.0976kg. Molality of the solution is:
0.345mol / 0.0976kg = 3.5325m
Replacing in the formulas:
a. Freezing point:
ΔT = 1.86C/m×3.5325m×1
ΔT = 6.57°C
0°C - Tfinal = 6.57°C
TFinal = -6.57°Cb. Boiling point:
ΔT = 0.51°C/m×3.5325m×1
ΔT = 1.80°C
Tfinal - 100°C = 1.80°C
Tfinal = 101.80°C
What does the atmosphere do for humans?
If a gas occupies 12.60 liters at a pressure of 1.50 atm, what will its pressure at a volume of 2.50 liters?
Answer:
7.56 atm
Explanation:
Boyle's law states that the pressure and volume of a gas are proportional to each other
The formular for Boyle's law is
P1V1=P2V2
According to the question above, the values given are
P1=1.50 atm
P2= ?
V1=12.60 litres
V2= 2.50 litres
Let us make P2 the subject of formular
P2= P1V1/V2
P2= 1.50×12.60/2.50
P2= 18.9/2.50
P2= 7.56 atm
Hence when the volume of a gas is 2.50 litres then it's pressure is 7.56 atm
The boiling point of ethanol is 78.40°C. A student conducts an
experiment and finds a boiling point of 75.70°C. How far off
from the accepted value was the student's result?
Error = °C
Answer:
2.7 °C
Explanation:
78.4-75.7=2.7
The student's result is 2.7° C less than the expected result.
We have a student conducting an experiment to find the boiling point of ethanol.
We have to determine how far off from the accepted value is the student's result.
What is Measurement error ?Measurement Error (also called Observational Error) is the difference between a measured quantity and its true value.
According to the question, we have -
True value of the boiling point of ethanol [T] = 78.40°C.
Measured value of the boiling point of ethanol [M] = 75.70°C.
The Error (E) in the measurement will be -
E = T - M
E = 78.40° - 75.70° = 2.7° C
Hence, the student's result is 2.7° C less than the expected result.
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calculate the moles of 25.2 g Na2S2O8
Answer:
To calculate the moles we must first find the molar mass M
M (Na2S2O8) = (23*2) + (32*2) + (16*8)
= 46 + 64 + 168
= 278g/mol
Molar mass = mass/moles
moles =mass / molar mass
= 25.2/278
= 0.0906mol
Hope this helps.
81. Find the pH of each mixture of acids. a. 0.115 M in HBr and 0.125 M in HCHO2 b. 0.150 M in HNO2 and 0.085 M in HNO3 c. 0.185 M in HCHO2 and 0.225 M in HC2H3O2 d. 0.050 M in acetic acid and 0.050 M in hydrocyanic acid
Answer:
See explanation below
Explanation:
This problem is a little long so I'm gonna be as clear as possible.
a) In this case we have two acids, HBr and HCHO2. Between these two acids, the HBr is the strongest, and does not have a Ka value to dissociate, while HCHO2 do.
In order to calculate pH we need the [H₃O⁺], and in this case, as HBr is stronger, the contribution of the weaker acid can be negligible, therefore, the pH of this mixture will be:
pH = -log[H₃O⁺]
pH = -log(0.115)
pH = 0.93
b) In this case it happens the same thing as part a) HNO₃ is the strongest acid, so the contribution of the HNO₂ which is a weak acid is negligible too, therefore the pH of this mixture will be:
pH = -log(0.085)
pH = 1.07
c) Now in this case, HCHO2 and HC2H3O2 are both weak acids, so to determine which is stronger, we need to see their Ka values. In the case of HCHO2 the Ka is 1.8x10⁻⁴ and for the HC2H3O2 the Ka is 1.8x10⁻⁵. Note that the difference between the two values of Ka is just 10¹ order, so, we can neglect the concentration of either the first or the second acid. We need to see the contribution of each acid, let's begin with the stronger acid first, which is the HCHO2, we will write an ICE chart to determine the value of the [H₃O⁺] and then, use this value to determine the same concentration for the second acid and finally the pH:
HCHO₂ + H₂O <-------> CHO₂⁻ + H₃O⁺ Ka = 1.8*10⁻⁴
i) 0.185 0 0
c) -x +x +x
e) 0.185-x x x
1.8*10⁻⁴ = x² / 0.185-x
As Ka is small, we can assume that "x is small" too, therefore the (0.185-x) can be rounded to just 0.185 so:
1.8*10⁻⁴ = x²/0.185
1.8*10⁻⁴ * 0.185 = x²
x² = 3.33*10⁻⁵
x = 5.77*10⁻³ M = [H₃O⁺]
Now that we have this concentration, let's write an ICE chart for the other acid, but taking account this concentration of [H₃O⁺] as innitial in the chart, and solve for the new concentration of [H₃O⁺] (In this case i will use "y" instead of "x" to make a difference from the above):
HC₂H₃O₂ + H₂O <--------> C₂H₃O₂⁻ + H₃O⁺ Ka = 1.8x10⁻⁵
i) 0.225 0 5.77x10⁻⁶
c) -y +y +y
e) 0.225-y y 5-77x10⁻³+y
1.8x10⁻⁵ = y(5.77x10⁻³+y) / 0.225-y ---> once again, y is small so:
1.8x10⁻⁵ = 5.77x10⁻³y + y² / 0.225
1.8x10⁻⁵ * 0.225 = 5.77x10⁻³y + y²
y² + 5.77x10⁻³y - 4.05x10⁻⁶ = 0
Solving for y:
y = -5.77x10⁻³ ±√(5.77x10⁻³)² + 4*4.05x10⁻⁶ / 2
y = -5.77x10⁻³ ±√4.95x10⁻⁵ / 2
y = -5.77x10⁻³ ± 7.04x10⁻³ / 2
y₁ = 6.35x10⁻⁴ M
y₂ = -6.41x10⁻³ M
We will take y₁ as the value, so the concentration of hydronium will be:
[H₃O⁺] = 5.77x10⁻³ + 6.35x10⁻⁴ = 6.41x10⁻³ M
Finally the pH for this mixture is:
pH = -log(6.41x10⁻³)
pH = 2.19
d) In this case, we have the same as part c, however the Ka values differ this time. The Ka for acetic acid is 1.8x10⁻⁵ while for HCN is 4.9x10⁻¹⁰. In this ocassion, we the difference in their ka is 10⁵ order, so we can neglect the HCN concentration and focus in the acetic acid. Let's do an ICE chart and then, with the hydronium concentration we will calculate pH:
HC₂H₃O₂ + H₂O <--------> C₂H₃O₂⁻ + H₃O⁺ Ka = 1.8x10⁻⁵
i) 0.050 0 0
c) -y +y +y
e) 0.050-y y y
1.8*10⁻⁵ = y² / 0.050-y
As Ka is small, we can assume that "y is small" too
1.8*10⁻⁵ = y²/0.050
1.8*10⁻⁵ * 0.050 = y²
y² = 9*10⁻⁷
y = 9.45*10⁻⁵ M = [H₃O⁺]
Finally the pH:
pH = -log(9.45x10⁻⁵)
pH = 3.02
