Calculate the pH at the equivalence point when 22.0 mL of 0.200 M hydroxylamine, HONH2, is titrated with 0.15 M HCl. (Kb for HONH2
Answer:
pH = 3.513
Explanation:
Hello there!
In this case, since this titration is carried out via the following neutralization reaction:
[tex]HONH_2+HCl\rightarrow HONH_3^+Cl^-[/tex]
We can see the 1:1 mole ratio of the acid to the base and also to the resulting acidic salt as it comes from the strong HCl and the weak hydroxylamine. Thus, we first compute the required volume of HCl as shown below:
[tex]V_{HCl}=\frac{22.0mL*0.200M}{0.15M}=29.3mL[/tex]
Now, we can see that the moles of acid, base and acidic salt are all:
[tex]0.0220L*0.200mol/L=0.0044mol[/tex]
And therefore the concentration of the salt at the equivalence point is:
[tex][HONH_3^+Cl^-]=\frac{0.0044mol}{0.022L+0.0293L} =0.0858M[/tex]
Next, for the calculation of the pH, we need to write the ionization of the weak part of the salt as it is able to form some hydroxylamine as it is the weak base:
[tex]HONH_3^++H_2O\rightleftharpoons H_3O^++HONH_2[/tex]
Whereas the equilibrium expression is:
[tex]Ka=\frac{[H_3O^+][HONH_2]}{[HONH_3^+]}[/tex]
Whereas Ka is computed by considering Kw and Kb of hydroxylamine:
[tex]Ka=\frac{Kw}{Kb}=\frac{1x10^{-14}}{9.10x10^{-9}} \\\\Ka=1.10x10^{-6}[/tex]
So we can write:
[tex]1.10x10^{-6}=\frac{x^2}{0.0858-x}[/tex]
And neglect the x on bottom to obtain:
[tex]1.10x10^{-6}=\frac{x^2}{0.0858}\\\\x=\sqrt{1.10x10^{-6}*0.0858}=3.07x10^{-4}M[/tex]
And since x=[H3O+] we obtain the following pH:
[tex]pH=-log(3.07x10^{-4})\\\\pH=3.513[/tex]
Regards!
Which if the following numbers in your personal life are exact numbers?
A. Your cell phone number
B. Your weight
C. Your IQ
D. Your driver's license number
E. The distance you walked yesterday
Answer:
I think D
Explanation:
Your cell phone number and your driver's license number are the numbers of your personal life that are exact.
In this context, an exact number refers to a number that if it undergoes any modification will not refer to the same thing that it referred to before that modification.
For example, my phone number is 12345. This number is exact because it cannot be changed because or else it would cease to be my phone number, that is, if someone wants to call me and writes the number 12346 it is no longer my number.
Addicionally, if my driver's license number is 112233 it is an exact number because if it is modified it would be the number of another driver.
According to the above, options B, C, and E are incorrect because they are inaccurate numbers because if they are modified they all refer to me and they would not change their meaning.
Learn more in: https://brainly.com/question/17093923
A hot metal plate at 150°C has been placed in air at room temperature. Which event would most likely take place over the next few minutes?
Molecules in both the metal and the surrounding air will start moving at lower speeds.
Molecules in both the metal and the surrounding air will start moving at higher speeds.
The air molecules that are surrounding the metal will slow down, and the molecules in the metal will speed up.
The air molecules that are surrounding the metal will speed up, and the molecules in the metal will slow down.
Answer:
The air molecules that are surrounding the metal will speed up, and the molecules in the metal will slow down.
Explanation:
There will be a transfer of thermal energy (heat) from the hot metal plate to the surrounding air. This transfer of energy equates to a transfer of kinetic energy in the molecules. As the plate loses heat, the molecules in the plate will lose kinetic energy and slow down. As the surrounding air gains heat, the molecules will gain kinetic energy and speed up.
Answer: C
Explanation:
Please if you just want point TELL ME I can’t fail this.
Match the environmental stresses to what would happen in the chemical reaction. Think through the path from the carbon cycle - how CO2
CO2is removed from the atmosphere and stored in sinks and then how CO2
CO2is released from sinks and/or produced. Loss of carbon sinks, like trees
Decrease in shellfish due to overfishing
Decrease the number of farms
Increase in Earth's temperature
Decrease in number of cars burning gas
Answer:
here you go. I took the test :)
Explanation:
The heat of combustion of ethane is -337.0kcal at 25 degrees celsius. what is the heat of the reaction when 3g of ethane is burnt completely
Answer:
Q = -33.6kcal .
Explanation:
Hello there!
In this case, according to the equation for the calculation of the total heat of reaction when a fixed mass of a fuel like ethane is burnt, we can write:
[tex]Q=n*\Delta _cH[/tex]
Whereas n stands for the moles and the other term for the enthalpy of combustion. Thus, for the required total heat of reaction, we first compute the moles of ethane in 3 g as shown below:
[tex]n=3g*\frac{1mol}{30.08g}=0.1mol[/tex]
Next, we understand that -337.0kcal is the heat released by the combustion of 1 mole of ethane, therefore, to compute Q, we proceed as follows:
[tex]Q=0.1mol*-337.0\frac{kcal}{mol}\\\\Q=-33.6kcal[/tex]
Best regards!
Ethanol (C2H5OH) is produced from the fermentation of sucrose in the presence of enzymes.
C12H22O11(aq) + H2O(g) 4 C2H5OH(l) + 4 CO2(g)
Determine the theoretical yield and the percent yields of ethanol if 665 g sucrose undergoes fermentation and 305.0 g ethanol is obtained.
theoretical
actual yield of ethanol = 305.0g
molar mass of sucrose = 342g
molar mass of ethanol =46g
mass of sucrose = 665g
mole of sucrose = mass / molar mass = 665/342
mole of sucrose =1.9 mole
sucrose : C2H5OH
1 : 4
1.9 : 1.9x4 =7.6 mole of C2H5OH are formed
mass (therotical yield ) of C2H5OH= mole x mass
mass (therotical yield ) of C2H5OH= 7.6 x 46 = 349.6g
percent yields of ethanol = actual /therotical x100
=305/349.6x100 = 87.24 %
how proved that carbon is present in sugar?
In all living organisms, in substances like carbohydrate, starch, urea etc. To prove sugar contains carbon, take a little amount of sugar in spoon and heat it gently till it melts and turned into yellowish color. On further heating it changes into brown colored mass and then black, which is charcoal.
Answer: sugar treated with strong sulphur acid turns to black
Explanation: sulphur acid removes water from sugars and carbon is left in residue.
This should not to try at home. Water boils when high temperature is achieved.
Also smell of burned sugar occurs
A chunk of zinc is added to a solution of gold (III) nitrate to extract the gold. The reaction forms,
zinc nitrate and the precipitate gold.
Explanation:
Gold (AU)................
The diagrams below show the alignment of the Sun, the Moon, and Earth.
Answer:A
Explanation: I learned it from a gizmo
What is a hot spot? Must be in your own words ( please hurry)
Answer:
It depends. what hot spot are you looking for?
Answer:
A hot spot is an area on Earth over a mantle plume or an area under the rocky outer layer of Earth, called the crust, where magma is hotter than surrounding magma. The magma plume causes melting and thinning of the rocky crust and widespread volcanic activity.
Explanation:
Hope this is what you mean be hot spot!
I hope this helps you!
1L = 1000 mL
Molarity (M) = moles of solute / L of solution
Calculate the moles of NaCl required to prepare 250 mL of 1.5 M aqueous solution.
Answer:· 44 g NaCl Explanation: The problem provides you with the molarity and volume of the target
Explanation:
In this field of sunflowers variation exists some flowers are tall others short
Answer:
Some flowers are tall, others short, and finally some plants are an intermediate height. The tallest plants shade the shorter; the taller plants are
Explanation:
3.0L of a gas is at a temperature of 78c. Find the volume of the gas at standard temperature
Answer:
V=2.33361811192L or 2.3x10
Explanation:
Using Charles law V1/T1=V2/T2 Remember to convert celcius to kelvin by using the standard temperature 273.15K
3L/(78C+273.15)=V/273.15
A change resulting in one or more new substances being formed is a?
A. nuclear reaction
B.physical property
C. chemical change
D.physical change
Answer:
C. Chemical change
Explanation:
A physical change is where something is changed but it doesnt affect the build up of the chemical. For example, if you broke sticks and threw them on the ground, that would be a physical change because the change is happening to the physical being of the object and not its chemical buildup. However, if you lit those sticks on fire, that would be considered a chemical change because you end up with two substances, ash and the remnants of the stick. A nuclear reaction would result in something blowing up so its not that. And a physical property is like what it looks like or how it smells. Hope I helped you!
What is the mass percent of potassium sulfate in solution if 78g of potassium sulfate is dissolved in 500 mL of water? (The density of water is 1.00 g/mL)
Answer:
13.5 %
Explanation:
First we calculate the mass of 500 mL of water, using its density:
Volume * Density = Mass500 mL * 1.00 g/mL = 500 gThen we calculate the mass percent of potassium sulfate, using the formula:
Mass of Potassium Sulfate / Total Mass * 100%
78 g / (78 + 500) g * 100 % = 13.5 %A sample of carbon dioxide gas at a pressure of 686 mm Hg and a temperature of 73 C, occupies a volume of 6.34 liters. If the gas is cooled at constant pressure to a temperature of 35 C, the volume of the gas sample will be ____________ L.
Recall the ideal gas law,
P V = n R T
Find the amount of CO₂ in the sample, n :
P = 686 mm Hg ≈ 91,459 Pa
V = 6.34 L
R = 8.3145 J/(mol•°K)
T = 73 °C = 346.2 °K
→ n = P V / (R T ) ≈ 0.20147 mol
Now find the volume V of the sample when the temperature T is 35 °C = 308.2 °K :
V = n R T / P ≈ 5.6349 L ≈ 5.63 L
Ammonia has been studied as an alternative "clean" fuel for internal combustion engines, since its reaction with oxygen produces only nitrogen and water vapor, and in the liquid form it is easily transported. An industrial chemist studying this reaction fills a tank with of ammonia gas and of oxygen gas, and when the mixture has come to equilibrium measures the amount of water vapor to be . Calculate the concentration equilibrium constant for the combustion of ammonia at the final temperature of the mixture. Round your answer to significant digits.
Answer:
0.364
Explanation:
Let's do an equilibrium chart for the reaction of combustion of ammonia:
2NH₃(g) + (3/2)O₂(g) ⇄ N₂(g) + 3H₂O(g)
4.8atm 1.9atm 0 0 Initial
-2x -(3/2)x +x +3x Reacts (stoichiometry is 2:3/2:1:3)
4.8-2x 1.9-(3/2)x x 3x Equilibrium
At equilibrium the velocity of formation of the products is equal to the velocity of the formation of the reactants, thus the partial pressures remain constant.
If pN₂ = 0.63 atm, x = 0.63 atm, thus, at equilibrium
pNH₃ = 4.8 - 2*0.63 = 3.54 atm
pO₂ = 1.9 -(3/2)*0.63 = 0.955 atm
pH₂O = 3*0.63 = 1.89 atm
The pressure equilibrium constant (Kp) is calculated with the partial pressure of the gases substances:
Kp = [(pN₂)*(pH₂O)³]/[(pNH₃)²*]
Kp = [0.63*(1.89)³]/[(3.54)²*]
Kp = 4.2533/11.6953
Kp = 0.364
What is the pressure exerted by 2.5 mol of gas with a temperature of 25 Celsius and a volume of 12.2 L
Answer:
5.01 atm
Explanation:
To answer this question, we're going to use the PV=nRT equation, where in this case:
P = ?V = 12.2 Ln = 2.5 molR = 0.082 atm·L·mol⁻¹·K⁻¹T = 25 °C ⇒ 25 + 273.16 = 298.16 KWe input the data:
P * 12.2 L = 2.5 mol * 0.082 atm·L·mol⁻¹·K⁻¹ * 298.16 KAnd finally solve for P:
P = 5.01 atmIf 4.0 g of helium gas occupies a volume of 22.4 L at 0 o C and a pressure of 1.0 atm, what volume does 3.0 g of He occupy under the same conditions?
Answer:
the volume occupied by 3.0 g of the gas is 16.8 L.
Explanation:
Given;
initial reacting mass of the helium gas, m₁ = 4.0 g
volume occupied by the helium gas, V = 22.4 L
pressure of the gas, P = 1 .0 atm
temperature of the gas, T = 0⁰C = 273 K
atomic mass of helium gas, M = 4.0 g/mol
initial number of moles of the gas is calculated as follows;
[tex]n_1 = \frac{m_1}{M} \\\\n_1 = \frac{4}{4} = 1[/tex]
The number of moles of the gas when the reacting mass is 3.0 g;
m₂ = 3.0 g
[tex]n_2 = \frac{m_2}{M} \\\\n_2 = \frac{3}{4} \\\\n_2 = 0.75 \ mol[/tex]
The volume of the gas at 0.75 mol is determined using ideal gas law;
PV = nRT
[tex]PV = nRT\\\\\frac{V}{n} = \frac{RT}{P} \\\\since, \ \frac{RT}{P} \ is \ constant,\ then;\\\frac{V_1}{n_1} = \frac{V_2}{n_2} \\\\V_2 = \frac{V_1n_2}{n_1} \\\\V_2 = \frac{22.4 \times 0.75}{1} \\\\V_2 = 16.8 \ L[/tex]
Therefore, the volume occupied by 3.0 g of the gas is 16.8 L.
The volume occupied by 3.0 g of He is mathematically given as
V2=16.8L
What volume does the 3.0 g of He occupy?Question Parameters:
If 4.0 g of helium gas occupies a volume of 22.4 L at 0 o C and a pressure of 1.0 atm, what volume does 3.0 g of H
Generally, the equation for the gas equation is mathematically given as
PV=nRT
When the reacting mass is 3g
n2=3/4
n2=0.75
Therefore
V1/n1=V2/n2
Where
n1=1
[tex]V2=\frac{22.4*0.75}{1}[/tex]
V2=16.8L
Read more about volume
https://brainly.com/question/1578538
How many calcium atoms are in 56.5 g of calcium?
Answer:
there are 8.501×10^23 atoms of Ca atoms
explain what you would do expect caesium astatide to look like .will it be soluble in water ?explain your reasoning
Answer:
it will not be soluble in water Becoz it can only be
separated by passing it through silver nitrate solution
Explanation:
i hope you understand
What are the two products of an acid base neutralization reaction?
Answer:
Neutralization reactions occur when two reactants, an acid and a base, combine to form the products salt and water.
Explanation:
*☆*――*☆*――*☆*――*☆*――*☆*――*☆*――*☆*――*☆**☆*――*☆*――*☆*――*☆
Answer: Water and NaCl is always formed
Explanation:
I hope this helped!
<!> Brainliest is appreciated! <!>
- Zack Slocum
*☆*――*☆*――*☆*――*☆*――*☆*――*☆*――*☆*――*☆**☆*――*☆*――*☆*――*☆
Would you rather wear
Socks in sandals or wear shoes without socks
Answer:
i always wear shoes without socks
Explanation:
What type of solution would have a pOH of 7
*☆*――*☆*――*☆*――*☆*――*☆*――*☆*――*☆*――*☆**☆*――*☆*――*☆*――*☆
Answer: None of these, because it is a neutral solution
Explanation:
I hope this helped!
<!> Brainliest is appreciated! <!>
- Zack Slocum
*☆*――*☆*――*☆*――*☆*――*☆*――*☆*――*☆*――*☆**☆*――*☆*――*☆*――*☆
Answer:
none of these
Explanation:
it should have a neutral solution
A sugar solution is 15% pure. How
many grams of sugar are there in 550
grams of the solution?
Answer:
Amount of sugar in solution = 82.5 gram
Explanation:
Given:
Sugar in solution percentage = 15%
Total solution = 550 grams
Find:
Amount of sugar in solution
Computation:
Amount of sugar in solution = Sugar in solution percentage x Total solution
Amount of sugar in solution = 15% X 550
Amount of sugar in solution = 82.5 gram
what makes up the cell menbrane
With few exceptions, cellular membranes — including plasma membranes and internal membranes — are made of glycerophospholipids, molecules composed of glycerol, a phosphate group, and two fatty acid chains. Glycerol is a three-carbon molecule that functions as the backbone of these membrane lipids.
Explanation:
the principal components of plasma membrane are lipids phospholipid and cholesterol proteins and carbohydrates
what happens when ?? Fresh red flower is introduced into a vessel contain Sulphur dioxide along
with moisture.
Describe how chemical reactions are affected by reaction conditions
of monction?
Answer:
hope his helps
Explanation:
Mention the factors affecting the rate of reaction
There are four main factors that can affect the reaction rate of a chemical reaction:
Reactant concentration. Increasing the concentration of one or more reactants will often increase the rate of reaction. ...
Physical state of the reactants and surface area. ...
Temperature. ...
Presence of a catalyst.
pleaaaaase helppppppppppppp ASAP
Answer:
Explanation:
a) The forward reaction is exothermic, hence when temperature is increased the equilibrium shift towards the reactants side to get rid of the excess energy. This will mean that more reactants are produced decreasing yield
b) There are a fewer number of moles of gas on the right side compared to the left side (Just count the coefficients before each compound) so a higher pressure will mean that the equilibrium will shift towards the products side in order to decrease the pressure. This will mean that more products are formed increasing yield
c) When something is powdered it's surface area to volume ratio increases. A higher surface area means that the particles around it have more area to work on so the frequency of collisions will increase increasing the rate of reaction. This is why iron is powdered.
A chemical reaction causes the chemical compositions of substances to change.
a. True
b. False
Answer:
True
Explanation:
A chemical change is otherwise known as a chemical reaction. A chemical change is characterized by the formation of new substances, evolution of heat and change in chemical composition of substances. The change in the composition of substances during a chemical change is the result of the making and breaking of chemical bonds during a chemical change.
A chemical change is not easily reversible because it involves changes in chemical composition of substances.
An example of a chemical change is the combination of sodium hydroxide and hydrochloric acid according to the reaction equation;
HCl(aq) + NaOH (aq) -----> NaCl(aq) + H2O (l)
We easily notice the change in the chemical composition of each of the substances involved in the reaction.