Answer:
The concentration of [tex]H^{+}[/tex] is 1.48 × [tex]10^{-9}[/tex] M
The absolute uncertainty of [tex][{H^{+}][/tex] is ±0.12 × [tex]10^{-9}[/tex] M
The concentration of [tex]H^{+}[/tex] is written as 1.48(±0.12) × [tex]10^{-9}[/tex] M
Explanation:
The pH of a solution is given by the formula below
pH = [tex]-log_{10}[{H^{+}][/tex]
∴ [tex][H^{+}] = 10^{-pH}[/tex]
where [tex][{H^{+}][/tex] is the [tex]H^{+}[/tex] concentration
From the question,
pH = 8.83±0.04
That is,
pH =8.83 and the uncertainty is ±0.04
First, we will determine [tex][{H^{+}][/tex] from
[tex][H^{+}] = 10^{-pH}[/tex]
[tex][{H^{+}] = 10^{-8.83}[/tex]
[tex][{H^{+}] = 1.4791[/tex] × [tex]10^{-9}[/tex] M
[tex][{H^{+}] = 1.48[/tex] × [tex]10^{-9}[/tex] M
The concentration of [tex]H^{+}[/tex] is 1.48 × [tex]10^{-9}[/tex] M
The uncertainty of [tex][{H^{+}][/tex] ( [tex]U_{[H^{+}] }[/tex] ) from the equation [tex][H^{+}] = 10^{-pH}[/tex] is
[tex]U_{[H^{+}] } = 2.303 \\[/tex] × [tex]{[H^{+}] }[/tex] × [tex]U_{pH }[/tex]
Where [tex]U_{[H^{+}] }[/tex] is the uncertainty of [tex][{H^{+}][/tex]
[tex]U_{pH }[/tex] is the uncertainty of the pH
Hence,
[tex]U_{[H^{+}] }[/tex] = 2.303 × 1.4791 × [tex]10^{-9}[/tex] × 0.04
[tex]U_{[H^{+}] }[/tex] = 1.36 × [tex]10^{-10}[/tex] M
[tex]U_{[H^{+}] }[/tex] = 0.12 × [tex]10^{-9}[/tex] M
Hence, the absolute uncertainty of [tex][{H^{+}][/tex] is ±0.12 × [tex]10^{-9}[/tex] M
In an experiment, shining which type of light on a strip of metal would be least likely to
produce the photoelectric effect?
ultraviolet light
dim blue light
bright red light
bright yellow light
Answer:
bright red light on edge
In an electromagnetic spectrum, bright red light would produce photoelectric effect on a strip of metal .
What is an electromagnetic spectrum?The electromagnetic spectrum consists of electromagnetic radiation consists of waves made up of electromagnetic field which are capable of propogating through space and carry the radiant electromagnetic energy.
The radiation are composed of electromagnetic waves which are synchronized oscillations of electric and magnetic fields . They are created due to change which is periodic in electric as well as magnetic fields.
In vacuum ,all the electromagnetic waves travel at the same speed that is with the speed of air.The position of an electromagnetic wave in an electromagnetic spectrum is characterized by it's frequency or wavelength.They are emitted by electrically charged particles which undergo acceleration and subsequently interact with other charged particles.
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Which piece of technology allowed scientists to look for life on Mars? a telescope a rover a microscope probeware
Answer:
A rover
I hope this helps!
Name the colourless gas that evolves when potassium reacts with water. How will you test this gas?
Answer:
Hydrogen gas
Explanation:
K +H2O=KOH+ H2
Test for hydrogen gas:
Light a splint and put it in the smoke present. If it makes a pop sound, that means hydrogen is present
A sample of 325 mg of neon occupies 2 dm^3 at 20.0 c. use the perfect gas law to determine the pressure of the gas.
Answer:
0.1935atm is the pressure of the gas.
Explanation:
In the problem you have the mass of Neon (You can obtain moles using molar mass), you have volume, and temperature. You can use general ideal gas law to solve pressure:
PV = nRT
P = nRT / V
Where P is pressure in atm, n are moles, R is gas constant (0.082atmL/molK), T is absolute temperature (20.0°C + 273.15 = 293.15K), and V is volume in L = Volume in dm³
Moles gas:
Molar mass Ne = 20.1797g/mol
0.325g * (1mol / 20.1797g) = 0.0161 moles
Replacing:
P = nRT / V
P = 0.0161 moles * 0.082atmL/molK * 293.15K / 2L
P = 0.1935atm is the pressure of the gas
Iron filings are attracted by a magnet. This is a physical property of iron but not of most other materials, including sand. How could you use this difference in physical properties to separate a mixture of iron filings and sand?
Answer:
Direct a magnet towards the mixture of iron and sand. You can observe that only the iron filling is attracted to the magnet and will come in contact with it. Therefore, after this process, you'll be left with iron filling on the surface of the magnet whereas the sand particles are left on the dish
To separate a mixture of iron filings and sand, using the physical property of iron is by using a magnet because a magnet attracts iron, but not sand.
What are physical properties?
Physical properties are those properties that can be seen by seeing an object or a substance. These properties do not change with the change in the composition of matter.
Physical properties are appearance, texture, color, odor, melting point, boiling point, density, solubility, polarity, and many others.
Magnetic properties are the property in which the object attracts to magnets and or iron-containing substances, here it can be used to separate sand and iron.
Thus, using a magnet and the magnetic property of iron—which attracts iron but not sand—one can separate a combination of iron filings and sand.
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1.05 Quiz: Measure Angles
When the reaction A → B + C is studied, a plot 1/[A]t vs. time gives a straight line with a positive slope. What is the order of the reaction?
Answer:
Second order
Explanation:
Given that:
When the reaction A → B + C is studied, a plot 1/[A]t vs. time gives a straight line with a positive slope.
From the integration method for the second order of reaction.
Suppose that:
rate = k₂[A]²
∴
[tex]\dfrac{1}{A}=\dfrac{1}{A_0}+k_2t[/tex]
Therefore, a plot of the linear function [tex]\dfrac{1}{A}[/tex] versus t will be linear with a positive slope k₂ and the intercept on the concentration axis will be [tex]\dfrac{1}{A_o}[/tex]
The linear plot for a second order reaction can be seen in theimage attached below.
Approximately 220 million tires are discarded in the U.S. each year. These tires present a disposal problem because they take up space, harbor pests, and have been known to catch fire. One tire can generate about 250,000 BTUs (1 BTU = 3 x 10 -4 kWh) when it is burned. The average American home consumes about 10,000 kWh of electricity per year. How many tires would be needed to meet the annual electricity demand of ten homes for one year if the production of electricity from tires is 50% efficient?
Answer:
2667 tires are needed to meet the demand of ten homes for one year.
Explanation:
According to the Second Law of Thermodynamics, only a part of generated energy when tires are burned can be utilized due to irreversibilities associated with finite temperature differences. The energy from a tire that can be transformed into electricity ([tex]E_{out}[/tex]), measured in kilowatt-hours, is estimated by definition of efficiency:
[tex]E_{out} = \eta \cdot E_{in}[/tex]
Where:
[tex]\eta[/tex] - Efficiency, dimensionless.
[tex]E_{in}[/tex] - Energy liberated by burning, measured in kilowatt-hours.
Given that [tex]\eta = 0.5[/tex] and [tex]E_{in} = 75\,kWh[/tex], the amount of energy per year generated by a tire is:
[tex]E_{out} = 0.5\cdot (75\,kWh)[/tex]
[tex]E_{out} = 37.5\,kWh[/tex]
Now, the amount of tires needed to meet the demand of then homes for one year is:
[tex]n = \frac{(10\,homes)\cdot \left(10000\,\frac{kWh}{home} \right)}{37.5\,\frac{kWh}{tire} }[/tex]
[tex]n = 2666.667\,tires[/tex]
2667 tires are needed to meet the demand of ten homes for one year.
The preferred conformation or Cis -3-tert - buty1-1- methyl cyclohexane is the one in which: _________.
A) the tert-butyl group is axial and the methyl group is equatorial.
B) the methyl group is axial and the tert-butyl group is equatorial.
C) both groups are axial.
D) both groups are equatorial.
E) the molecule exists in a boat conformation.
Answer:
D) both groups are equatorial.
Explanation:
To solve this question we can start by drawing the molecule in using the structure of the hexagon. In this structure, we have the methyl group on carbon 1 and the terbutyl group on carbon 3, additionally, if we have a cis structure both groups must have the same type of bond (in this case the wedge bond). (See figure 1)
When we write the chair structure, we must keep the same structure. That is, methyl must be on carbon 1 and terbutyl on carbon 3. Also, the cis configuration must be maintained. With this in mind, we can choose the equatorial configuration for methyl on carbon 1 (since the position equatorial is the one that has less steric impediment and more stability). If this is true for carbon 1, we must place the terbutyl group on carbon 3 in the same configuration (i.e. cis). Therefore, on carbon 3 we must place the tert-butyl down on carbon 3, that is, in the equatorial position. (See figure 1).
Therefore, in the chair-like structure, both groups must be in an equatorial position.
I hope it helps!
2. Bart finds a solid shiny
object and he hopes it is made
of gold! It has a mass of
110.0 g and it has a volume of
10.0 mL
a) What is the density of the
metal object?
b) Could the object be made
of gold?
Answer:
1. Density of metal object = 11000 kg / m3.
2. Could the object be gold = No,because the density of gold is 19300 kg / m3.
Please someone can help with this answer?
Answer:
6,000kg/m3
Explanation:
6.00g/1cm3 x 1kg/1000g x 1cm3/0.000001m3
= 6.00kg/0.001m3
= 6,000kg/m3
Q 11.8: Exposure of 2-methyl-2-butene to oxymercuration-demercuration conditions provides which product?
Answer:
Exposure of 2-methyl-2-butene to oxymercuration-demercuration conditions provides 2-methyl-2-butanol.
Explanation:
Please see the attachments below
what are the characterestics of a point group?
Explanation:
Maybe this answer is helpful for you... Any questions regarding the answer.. U can ask me.. ☺️
what should you do with all lab equipment at the conclusion of a Lab
Answer:
I think the teacher was supposed to tell u the answer to that
A 100.0 mL buffer solution is 0.175 M in HClO and 0.150 M in NaClO. What is the pH after addition of 0.090 g of NaOH?A
Answer:
pH = 7.51
Explanation:
The pKa of the HClO/NaClO buffer is 7.46. To determine the pH of this buffer we can use H-H equation:
pH = pKa + log [A⁻] / [HA]
pH = 7.46 + log [NaClO] / [HClO]
Where [] is molarity -or moles- of each compound
Initial moles of HClO and NaClO:
HClO: 0.100L * (0.175mol / L) = 0.0175 moles HClO
NaClO: 0.100L * (0.150mol / L) = 0.0150 moles NaClO
Now, HClO reacts with NaOH producing NaClO:
HClO + NaOH → NaClO + H₂O
The moles of NaOH that reacts (Molar mass: 40g/mol) are:
0.090g * (1mol / 40g) = 0.00225 moles NaOH.
That means after the reaction, 0.00225 moles of HClO are consumed and 0.00225 moles of NaClO are produced.
And after the reaction, moles are:
Final moles:
HClO: 0.0175 mol - 0.00225 mol = 0.01525 moles
NaClO: 0.0150 mol + 0.00225 mol = 0.01725 moles
Replaing in H-H equation:
pH = 7.46 + log [0.01725moles] / [0.01525moles]
pH = 7.51What function does adding a coefficient in a chemical equation serve?
Answer:
coefficients increase the products to increase the efficiency of the reaction.Coefficients balance the equation with respect to the law of conversation of mass. coefficients also increases the reactants to help the reaction proceed.
Calculate the heat (in calories) required to freeze 35.0 g of water.
Answer:
-2.79 × 10³ cal
Explanation:
Step 1: Given data
Mass of water (m): 35.0 gLatent heat of fusion of water (L): -79.7 cal/gStep 2: Calculate the heat required to freeze 35.0 g of water
We have 35.0 g of liquid water and we want to freeze it, that is, to convert it in 35.0 g of ice (solid water), at 0 °C (melting point). We can calculate the heat (Q) that must be released using the following expression.
Q = L × m
Q = -79.7 cal/g × 35.0 g
Q = -2.79 × 10³ cal
The heat in calories required to freeze 35.0g of water of water is 2.79 × 10³ cal.
HOW TO CALCULATE HEAT:The heat of a water in the mass of water can be calculated as follows:Q = L × m
Where;
Q = quantity of heat (calories)L = latent heat of fusion of waterm = mass of waterAccording to this question;
Mass of water (m): 35.0 gLatent heat of fusion of water (L): -79.7 cal/gQ = L × m
Q = -79.7 cal/g × 35.0 g
Q = -2.79 × 10³ calories
Therefore, the heat in calories required to freeze 35.0g of water of water is 2.79 × 10³ cal.
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The central Xe atom in the XeF4 molecule has ________ unbonded electron pair(s) and ________ bonded electron pair(s) in its valence shell.
Answer:
XeF4 has two unbounded pairs of electrons and four bonded pairs of electrons on its valence shell
Explanation:
XeF4 is a square planar compound with Xe-F distance of about 1.95 angstroms. The compound has six electron pair domains on its outermost shell. Four bond pairs occupy four corners of a square to give a square planar geometry while two electron pairs are found above and below the plane of the square.
Hence the molecule is square planar.
What is the mass of a bar of aluminum with length 5.3cm, width 0.32 cm and height 2.34cm? The density of aluminum is 2.70g/cm3.
Answer:
mass = 10.72 gExplanation:
Density of a substance can be found by using the formula
[tex]Density = \frac{mass}{volume} [/tex]
Making mass the subject we have
[tex]mass = Density \times volume[/tex]
From the question
Density = 2.70 g/cm³
We assume that the aluminum is a cuboid
and volume of a cuboid is given by
Volume = length × width × height
length = 5.3 cm
width = 0.32 cm
height = 2.34 cm
Volume = 5.3 × 0.32 × 2.34 = 3.97 cm³
Substitute the values into the above and solve for the mass
We have
mass = 2.70 × 3.97
We have the final answer as
mass = 10.72 gHope this helps you
How many grams of solid potassium chlorate (KClO 3, 122.55 g/mol) are needed to make 150 mL of 0.50 M solution
Answer:
[tex]m_{solute}=9.19gKClO_3[/tex]
Explanation:
Hello,
In this case, since the molarity is defined as:
[tex]M=\frac{mol_{solute}}{V_{solution}}[/tex]
Whereas the volume of the solution is in liters, we first compute the moles of solute which in this case is the potassium chlorate:
[tex]mol_{solute}=150mL*\frac{1L}{1000mL}*0.50molKClO_3/L \\\\mol_{solute}=0.075molKClO_3[/tex]
Then, by using its molar mass of 122.55 g/mol, we compute the required mass as follows:
[tex]m_{solute}=0.075molKClO_3*\frac{122.55gKClO_3}{1molKClO_3} \\\\m_{solute}=9.19gKClO_3[/tex]
Regards.
why ice floats on water is a physical change
Answer:
Ice floats on water because it is less dense than water. When water freezes into its solid form, its molecules are able to form more stable hydrogen bonds locking them into positions. Because the molecules are not moving, they're not able to form as many hydrogen bonds with other water molecules. Ice is a unique substance because it is solid-state — ice — is less dense than its liquid state. Because of this property, ice floats in water. Physical properties are characteristics of a substance. They do not change. Ice floats on water because it is less dense than water. When water freezes into its solid form, its molecules are able to form more stable hydrogen bonds locking them into positions.
To draw a primary amine, start by drawing the longest carbon atom chain of the molecule. Next, connect the amine functional group according to the location given in the name of the amine. Finally, attach all substituent groups according to the location given in the nomenclature. To draw a secondary or tertiary amine, start by drawing a nitrogen atom with three connecting bonds. Attach each substituent group, listed in the nomenclature by the prefix N-, to the nitrogen atom (two groups if it is a secondary amine and three groups if it is a tertiary amine). For secondary amines, attach a hydrogen atom to the third bond of the nitrogen atom.
A. Draw the structure of 1,4-hexanediamine.
B. Draw the structure of 2,4-difouroaniline.
Answer:
See figure 1 and figure 2
Explanation:
We can analyze each structure:
A. Structure of 1,4-hexanediamine
For this molecule, we must start with a six-carbon chain. Since, in the name of the molecule we have the prefix "hex", then we have to name the carbons. The first carbon will be the one on the right and the sixth on the left. Finally, we must place two amino groups on carbons 1 and 4 (See figure 1).
B. Draw the structure of 2,4-difluoroaniline
For this molecule, we must start with the aniline molecule. In this molecule, we have an amino group attached to a benzene ring. Carbon number 1 will be the carbon that is attached to the amino group, carbon number 2 must be placed in a clockwise direction. Finally, we must place two fluorine atoms on carbons 2 and 4 (See figure 2).
Write the condensed structural formula for the major organic product of the following reaction in the presence of light (assume that only one mole of Br2 reacted). Name the reaction mechanism and summarize in words the main steps of the mechanism.
(CH3)4C + Br2
Answer:
(CH3)3CCH2Br
Explanation:
This reaction proceeds by the following mechanism;
First, irradiation with light of appropriate frequency leads to the homolytic fission of the bromine molecule to yield two bromine free radicals. This is the initiation step of the reaction.
The free radical now attacks one of the -CH3 groups in neopentane leading to the formation of (CH3)3CCH2Br.
Calculate the percentrage of neutral form of aspirin that is present in the stomach ph 1.
Answer:
The 99.68% of the aspirin is present in the neutral form
Explanation:
Aspirin, Acetylsalicylic acid, is a weak acid with pKa = 3.5
Using Henderson-Hasselbalch equation:
pH = pKa + log [A⁻] / [HA]
Where [A⁻] is the ionized form and HA the neutral form of the acid
Replacing with a pH of stomach of 1.0:
1.0 = 3.5 + log [A⁻] / [HA]
-2.5 = log [A⁻] / [HA]
3.16x10⁻³ = [A⁻] / [HA] (1)
A 100% of aspirin is = [A⁻] + [HA]
100 = [A⁻] + [HA] (2)
Replacing (2) in (1)
3.16x10⁻³ = 100 - [HA] / [HA]
3.16x10⁻³[HA] = 100 - [HA]
1.00316 [HA] = 100
[HA] = 99.68%
The 99.68% of the aspirin is present in the neutral formYou need to show how the time it takes for a rat to finish a maze changes in different age
groups. What chart or graph should you use?
O Line Graph
Bar Chart
O Pie Chart
O Histogram
O Scatter Plot
I would give brainly
define the term solubility,saturated solution, solubility product constant
Answer:
Hey!I will try to help with the ones I know.
solubility is a means of comparing the extent to which different solutes can dissolve in a particular solvent at a definite temperature.
A saturated solution of a solute at a particular temperature is one which contains as much solute as it can dissolve at that temperature in the presence of undissolved solute particles....
This is what I know I hope it helps you
There is an electrolytic cell in which Mn2+ is reduced to Mn and Sn is oxidized to Sn2+.
A. Write an equation for the half-reaction occurring at each electrode. Express your answers as chemical equations separated by a comma. Identify all of the phases in your answer.
B. What minimum voltage is necessary to drive the reaction? Vmin =
Answer:
-1.05 V
Explanation:
At the anode;
Sn(s) -----> Sn^2+(aq) + 2e
At the cathode;
Mn^2+(aq) + 2e ------> Mn(s)
Given that it is an electrolytic cell,
E°cell= E°cathode - E°anode
But;
E°cathode= -1.19 V
E°anode= -0.14 V
E°cell= -1.19-(-0.14)
E°cell= -1.05 V
Therefore
Vmin = -1.05 V
What is the main reason that Absolute Zero has not been achieved under laboratory conditions?
Answer:
The reason is because Charle's Law which states that volume is directly proportional to temperature. So, for the temperature to be absolute zero, there would need to be no volume. It's Impossible.
Explanation:
The principal quantum number for the outermost electrons in a Te atom in the ground state is ________.
Answer:
The principal quantum number for the outermost electrons in a Te atom in the ground state is 5
Explanation:
In quantum chemistry, the region of maximum probability of where an electron is located is sometimes referred to as cloud or orbital.
The principal quantum number is used to express the state of an electron
The principal quantum number for the outermost electrons in a Te atom in the ground state is 5
The atomic number of Tellurium Te is Kr 4d¹⁰ 5s² 5p⁴
so quantum no is 5
basketane is a hydrocarbon that is 90.8% carbon. If the molar mass is between 130-140 g/mol find the molecular formula of the compound.
Answer:
C₁₀H₁₂
Explanation:
90.8% of basketane (Hydrocarbon, contains only C and H) is Carbon, and 100-90.8 = 9.2% of the mass is hydrogen.
The molar mass is between 130-140g/mol, That means the moles of Carbon (Using its molar mass, 12.01g/mol) that are in basketane are between:
140g/mol /12.01g/mol *90.8%= 10.58 moles of C.
130g/mol / 12.01g/mol *90.8%= 9.83 moles of C.
As the moles of carbon must be given in a whole number, There are 10 moles of Carbon.
10 moles C * (12.01g / mol) = 120.1g/mol that are 90.8% of the molar mass. Molar mass of basketane is:
100% * (120.1g/mol / 90.8%) =
132.3g/mol.
The part of the molar mass due hydrogen must be:
132.3 g/mol - 120.1g/mol = 12.2 g/mol
As molar mass of hydrogen is 1g/mol, the moles of hydrogen are 12
And molecular formula is:
C₁₀H₁₂