The uncertainties of the delta measurements and the uncertainty of the atomic weight derivedfrom the best measurement of isotopic abundances constrain the number of significant figures in theatomic-weight values of the upper and lower bounds. For carbon, the fifth digit after the decimal pointis uncertain because of the uncertainty value of 0.000 027. Therefore, the number of significant digitsin the atomic-weight value is reduced to four figures after the decimal point. The Commission may rec-ommend additional conservatism and reduce the number of significant figures further. For the lowerbound of carbon, 12.009 635 is truncated to 12.0096. For an upper bound, the trailing digit is increasedto ensure the atomic-weight interval encompasses the atomic-weight values of all normal materials. Inthe case of carbon, the upper bound is adjusted from 12.011 532 to 12.0116 to express four digits afterthe decimal point. The lower and upper bounds are evaluated so that the number of significant digits ineach is identical. If a value ends with a zero, it may need to be included in the value to express therequired number of digits. The following are examples of lower and upper atomic-weight bounds foroxygen that could be published by the Commission in its various tables.
---------------------------
Extracted from" Atomic weights of the elements 2009 (IUPAC Technical Report)"
4.Calculate the Hydroxide, Hydrogen ion and POH of solution if the PH of solution is 7.b
5.Solution A Has PH =4 and solution B has PH = 7.How many times greater is the Hydroxide ion
concentration in solution A than the Hydronium ion concentration in solution B
the ph is gonna be your value and the 4 is gonna be your main subject
so as the ph is your value u gonna ad your ph and 7 and 4 toghter then multiple your answer 2 times because ph represent multiple and your value
Three resonance structures of the given anion are possible. One is given, but it is incomplete. Complete the given structure by adding nonbonding electrons and formal charges. Draw the two remaining resonance structures (in any order), including nonbonding electrons and formal charges. Omit curved arrows.
Answer:
Explanation:
The missing incomplete resonance structure is attached in the image below. From there, we can see the addition of the nonbonding electrons and its' formal charge which makes the resonance structure a complete resonance structure. The others two resonance structure that can be derived from the complete structure is also shown in the image. Out of these three structures, the structure that contributes most to the hybrid is the structure with the negative charge on the oxygen.
Which of the following is the least important property of a mineral?
A streak
B hardness
C luster
D color
Explanation:
Türküm lben .Türk varmi kardaşlar!!!
Answer:
D color
Explanation:
One physical test for minerals is to check their color. Certain kinds of minerals always have a similar color, but most minerals have a range of colors. This is the least informative property of a mineral. Some words to describe color are: pale, bright, streaked, splotchy, banded, and speckled.
This is from my school assignment good luck everyone!! :D
How many moles of hydrogen react with 4.5 moles of oxygen to synthesize water?
Answer:
9moles of hydrogen gas
Explanation:
To solve this problem, we write the reaction expression first;
2H₂ + O₂ → 2H₂O
We have been given the number of moles of oxygen gas to be:
Number of moles of oxygen gas = 4.5moles
From the balanced reaction expression:
1 mole of oxygen gas reacts with 2 moles of hydrogen gas
4.5moles of oxygen gas will react with 4.5 x 2 = 9moles of hydrogen gas
The energy stored in an object is called potential energy
True or false
its true
Potential energy is the stored or latent energy in an object at rest. It’s fundamental to many physics-related concepts because its laws hold true on any level, from the planetary to the atomic level. The potential energy of an object is measurable.
Which water usage uses the least amount of water in a year in the United States? a industry
b livestock c irrigation d public water supply
plzzzzzzzz hurrrrry
Iron and vanadium both have the BCC crystal structure and V forms a substitutional solid solution in Fe for concentrations up to approximately 20 wt.% V at room temperature. Determine the concentration in weight percent of V that must be added to iron to yield a unit cell edge length of 0.289 nm.
Answer:
Explanation:
To find the concentration; let's first compute the average density and the average atomic weight.
For the average density [tex]\rho_{avg}[/tex]; we have:
[tex]\rho_{avg} = \dfrac{100}{ \dfrac{C_{Fe} }{\rho_{Fe}} + \dfrac{C_v}{\rho_v} }[/tex]
The average atomic weight is:
[tex]A_{avg} = \dfrac{100}{ \dfrac{C_{Fe} }{A_{Fe}} + \dfrac{C_v}{A_v} }[/tex]
So; in terms of vanadium, the Concentration of iron is:
[tex]C_{Fe} = 100 - C_v[/tex]
From a unit cell volume [tex]V_c[/tex]
[tex]V_c = \dfrac{n A_{avc}}{\rho_{avc} N_A}[/tex]
where;
[tex]N_A[/tex] = number of Avogadro constant.
SO; replacing [tex]V_c[/tex] with [tex]a^3[/tex] ; [tex]\rho_{avg}[/tex] with [tex]\dfrac{100}{ \dfrac{C_{Fe} }{\rho_{Fe}} + \dfrac{C_v}{\rho_v} }[/tex] ; [tex]A_{avg}[/tex] with [tex]\dfrac{100}{ \dfrac{C_{Fe} }{A_{Fe}} + \dfrac{C_v}{A_v} }[/tex] and
[tex]C_{Fe}[/tex] with [tex]100-C_v[/tex]
Then:
[tex]a^3 = \dfrac { n \Big (\dfrac{100}{[(100-C_v)/A_{Fe} ] + [C_v/A_v]} \Big) } {N_A\Big (\dfrac{100}{[(100-C_v)/\rho_{Fe} ] + [C_v/\rho_v]} \Big) }[/tex]
[tex]a^3 = \dfrac { n \Big (\dfrac{100 \times A_{Fe} \times A_v}{[(100-C_v)A_{v} ] + [C_v/A_Fe]} \Big) } {N_A \Big (\dfrac{100 \times \rho_{Fe} \times \rho_v }{[(100-C_v)/\rho_{v} ] + [C_v \rho_{Fe}]} \Big) }[/tex]
[tex]a^3 = \dfrac { n \Big (\dfrac{100 \times A_{Fe} \times A_v}{[(100A_{v}-C_vA_{v}) ] + [C_vA_Fe]} \Big) } {N_A \Big (\dfrac{100 \times \rho_{Fe} \times \rho_v }{[(100\rho_{v} - C_v \rho_{v}) ] + [C_v \rho_{Fe}]} \Big) }[/tex]
Replacing the values; we have:
[tex](0.289 \times 10^{-7} \ cm)^3 = \dfrac{2 \ atoms/unit \ cell}{6.023 \times 10^{23}} \dfrac{ \dfrac{100 (50.94 \g/mol) (55.84(g/mol)} { 100(50.94 \ g/mol) - C_v(50.94 \ g/mol) + C_v (55.84 \ g/mol) } }{ \dfrac{100 (7.84 \ g/cm^3) (6.0 \ g/cm^3 } { 100(6.0 \ g/cm^3) - C_v(6.0 \ g/cm^3) + C_v (7.84 \ g/cm^3) } }[/tex]
[tex]2.41 \times 10^{-23} = \dfrac{2}{6.023 \times 10^{23} } \dfrac{ \dfrac{100 *50*55.84}{100*50.94 -50.94 C_v +55.84 C_v} }{\dfrac{100 * 7.84 *6}{600-6C_v +7.84 C_v} }[/tex]
[tex]2.41 \times 10^{-23} (\dfrac{4704}{600+1.84 C_v})=3.2 \times 10^{-24} ( \dfrac{284448.96}{5094 +4.9 C_v})[/tex]
[tex]\mathbf{C_v = 9.1 \ wt\%}[/tex]
= 1
= 2
5
= 3
10
= 6
7
8
Write a balanced half-reaction for the reduction of gaseous oxygen (02) to liquid water
to liquid water (H2O) in acidic aqueous solution. Be sure to add physical state symbols
where appropriate.
a
A balanced half-reaction :
O₂(g)+ 4H⁺(aq)+ 4e⁻⇒2H₂O(l)
Further explanationGiven
Reduction of gaseous oxygen (O₂) to liquid water(H₂O)
Required
A balanced half-reaction
Solution
Step 1 : Equalize the number of elements by adding coefficients
Equates element O
O₂(g)⇒2H₂O(l)
Step 2 : Equalize H by adding H⁺ on the opposite side (the deficient area of H).
O₂(g)+ 4H⁺(aq)⇒2H₂O(l)
Step 3 : Equalized the charge using the addition of electrons (e⁻) along the H⁺ field.
O₂(g)+ 4H⁺(aq)+ 4e⁻⇒2H₂O(l)
A chemist adds 0.60L of a 0.20/molL sodium thiosulfate Na2S2O3 solution to a reaction flask. Calculate the millimoles of sodium thiosulfate the chemist has added to the flask. Round your answer to 2 significant digits. (in mmol)
Answer:
1.2×10² mmole of Na₂S₂O₃
Explanation:
From the question given above, the following data were obtained:
Volume = 0.6 L
Molarity = 0.2 mol/L
Mole of Na₂S₂O₃ =?
Molarity is simply defined as the mole of solute per unit litre of water. Mathematically, it is expressed as:
Molarity = mole /Volume
With the above formula, we can obtain the number of mole of Na₂S₂O₃ in the solution as illustrated below:
Volume = 0.6 L
Molarity = 0.2 mol/L
Mole of Na₂S₂O₃ =?
Molarity = mole /Volume
0.2 = Mole of Na₂S₂O₃ / 0.6
Cross multiply
Mole of Na₂S₂O₃ = 0.2 × 0.6
Mole of Na₂S₂O₃ = 0.12 mole
Finally, we shall convert 0.12 mole to millimole (mmol). This can be obtained as follow:
1 mole = 1000 mmol
Therefore,
0.12 mole = 0.12 mole × 1000 mmol / 1 mole
0.12 mole = 120 = 1.2×10² mmole
Thus, the chemist added 1.2×10² mmole of Na₂S₂O₃
The 10x SDS gel electrophoresis buffer contains 250mM Tris HCl, 1.92M Glycine, and 1% (w/v) SDS. Buffers are always used at 1x concentration in the lab (unless specified otherwise in the protocol), so you will have to dilute the 10x buffer to 1x before use. What is the concentration of Tris and SDS in the 1x buffer
Answer:
25 mM Tris HCl and 0.1% w/v SDS
Explanation:
A 10X solution is ten times more concentrated than a 1X solution. The stock solution is generally more concentrated (10X) and for its use, a dilution is required. Thus, to prepare a buffer 1X from a 10X buffer, you have to perform a dilution in a factor of 10 (1 volume of 10X solution is taken and mixed with 9 volumes of water). In consequence, all the concentrations of the components are diluted 10 times. To calculate the final concentration of each component in the 1X solution, we simply divide the concentration into 10:
(250 mM Tris HCl)/10 = 25 mM Tris HCl
(1.92 M glycine)/10 = 0.192 M glycine
(1% w/v SDS)/10 = 0.1% w/v SDS
Therefore the final concentrations of Tris and SDS are 25 mM and 0.1% w/v, respectively.
A reaction between liquid reactants takes place at in a sealed, evacuated vessel with a measured volume of . Measurements show that the reaction produced of sulfur hexafluoride gas. Calculate the pressure of sulfur hexafluoride gas in the reaction vessel after the reaction. You may ignore the volume of the liquid reactants. Round your answer to significant digits.
Answer:
0.41 atm
Explanation:
A reaction between liquid reactants takes place at 10.0 °C in a sealed, evacuated vessel with a measured volume of 5.0 L. Measurements show that the reaction produced 13. g of sulfur hexafluoride gas. Calculate the pressure of sulfur hexafluoride gas in the reaction vessel after the reaction. You may ignore the volume of the liquid reactants. Round your answer to 2 significant digits.
Step 1: Given data
Temperature (T): 10.0 °CVolume of the vessel (V): 5.0 LMass of sulfur hexafluoride gas (m): 13. gStep 2: Convert "T" to Kelvin
We will use the following expression.
K = °C + 273.15
K = 10.0 °C + 273.15 = 283.2 K
Step 3: Calculate the moles (n) of SF₆
The molar mass of SF₆ is 146.06 g/mol.
13. g × 1 mol/146.06 g = 0.089 mol
Step 4: Calculate the pressure (P) of SF₆
We will use the ideal gas equation.
P × V = n × R × T
P = n × R × T/V
P = 0.089 mol × (0.0821 atm.L/mol.K) × 283.2 K/5.0 L = 0.41 atm
Analyze: What pattern do you see? Make a rule: Based on your data, how are elements arranged into chemical families?
Answer: in order of increasing atomic number.
Explanation: Elements in the same group have similar chemical properties. This is because they have the same number of outer electrons and the same valency.
Answer:
What pattern do you see?
Chemical families have the same number of valence electrons.
Make a rule: Based on your data, how are elements arranged into chemical families?
They are arranged vertically depending on how many valence electrons they have, if they have the same amount, they will have the same chemical family in each column.
An ionic compound has a generic formula of QR2.
Which elements could the Q and R represent?
Once you choose an answer, check it by plugging those elements into the QR2 formula to see if it looks right.
Q= Sodium R= Oxygen
Q= Magnesium R= Chlorine
Q= Oxygen R= Sodium
Q= Chlorine R= Magnesium
Answer:
Q= Magnesium R= Chlorine
Explanation:
The element Q should be magnesium and R is chlorine.
An ionic compound is a compound that is formed by the combination of a metal and non-metal. Such bonds forms when there is a transfer of electrons from the metals to the non-metals. This leaves a net positive charge on the metal and a negative charge on the non-metal.
The electrostatic attraction leads to the formation of the bond.
To solve this problem, the hypothetical compound is QR₂
Mg Cl
2 8 2 2 8 7
So, Mg transfers 2 electrons to two atoms of chlorine.
This leads to the formation of the compound MgCl₂
How does heat travel?
1. From cold things to hotter things
2. From hot things to colder things
3. Between things of the same temperature
Answer:
well heat travels by conduction, convection, and radiation but I think it's 2.
Explanation:
heat travels to colder things trying to make a balanced temperature for both of the objects.
Where would a disease transmitted by person to person contact be most likely to spread quickly
Answer: inside
Explanation:
Answer:
direct and indirect contact
Explanation:
if you touch a doorknob right after an infected person than you make be exposed to the disease.
Photosynthesizing organisms use ____
to produce glucose.
Answer: Photosynthesizing organisms use carbon dioxide and water to produce glucose.
Explanation:
Photosynthesis is a phenomenon in which green plants containing chlorophyll use sunlight as a source of energy to convert carbon dioxide and water to form glucose and oxygen.
Photosynthesis is the process used by plants, algae and certain bacteria to convert energy from sunlight and turn it into chemical energy in the form of glucose which is used a s a source of energy by many organisms.
[tex]6CO_2+6H_2O\overset{sunlight}\rightarrow C_6H_{12}O_6+6O_2[/tex]
Problem 3 A sample of 2.37 moles of an ideal diatomic gas experiences a temperature increase of 65.2 K at constant volume. (a) Find the increase in internal energy if only translational and rotational motions are possible. (b) Find the increase in internal energy if translational, rotational, and vibrational motions are possible. (c) How much of the energy calculated in (a) and (b) is translational kinetic energy?
Answer:
a) the increase in internal energy is 3211.78 J
b) dU = 3854.14 J
c) dU[tex]_{T}[/tex] = 1927.06 J
Explanation:
Given the data in question;
Foe a diatomic gas, the degree of freedom are as follow;
lets consider the positional degree of freedom
transitional df = 3
rotational df = 2
vibrational ff = 1
now, the internal energy given by;
U = Nf × 1/2NKT = Nf×1/2×nRT
where Nf is the number of degree of freedom
N is Number of atoms or molecules
n = number of molecules
L is Boltzmann constant
R is universal gas constant
so change in internal energy , change in T is given by
dU = Nf × 1/2 × nT dT
n = 2.37 moles
dT = 65.2 K
R = 8.314 J/mol.J
a)
Find the increase in internal energy if only translational and rotational motions are possible
since rotational and transitional motion are involved ;
Nf = 3(trasitional) + 2(rotational) = 5
so,
dU = 5 × 1/2 × nRdT
we substitute
dU = 5 × 0.5 × 2.37 × 8.314 × 65.2
dU = 3211.78 J
Therefore, the increase in internal energy is 3211.78 J
b)
Find the increase in internal energy if translational, rotational, and vibrational motions are possible.
Nf = 3 + 2 + 1 = 6
dU = 6 × 1/2 × nRdT
dU = 6 × 0.5 × 2.37 × 8.314× 65.2
dU = 3854.14 J
c)
How much of the energy calculated in (a) and (b) is translational kinetic energy?
dU[tex]_{T}[/tex] = 3 × 0.5 × 2.37 × 8.314 × 65.2
dU[tex]_{T}[/tex] = 1927.06 J
(The stands for a number the student is going to calculate.)
The ___________ stands for a number the student is going to calculate. Fill in the missing part of this equation.
(87. 1/mmole. C). ______= _____ kJ/mol.C
Answer:
1000 kJ.mmole / 1000 J.mole
Explanation:
To solve this, we need to analyze the given data.
We have a number which is 87.1 J/mmole.C (I'm assuming it has the J at the beggining because if not, then you are missing some data) and the final result is kJ/mol.C
The only unit that has not changed in the process was the °C, while the mole and J change respectively. In this case, we need to know the conversion factor of mmole to mole and J to kJ.
In the case of a mole:
1 mole --------> 1000 mmole
In the case of Joule:
1 kJ ----------> 1000 J
So the first thing we will do is to change from J to kJ:
87.1 J * 1 kJ / 1000 J = 0.0871 kJ
Now let's convert mmol to mole:
0.0871 kJ/mmole.C * 1000 mmole / 1 mole = 87.1 kJ/mole.C
As you can see, there's is practicly no change at all with the units, so putting all together it would be:
87.1 J/mmole.C * 1000 kJ.mmole / 1000 J.mole = 87.1 kJ/mole.°CHope this helps
Calculate the molarity (M) if 3.35g of H3PO4 is dissolved in water to give a total volume of 200mL
Answer:
0.171 M
Explanation:
Step 1: Given data
Mass of H₃PO₄ (solute): 3.35 gVolume of solution (V): 200 mLStep 2: Calculate the moles of solute
The molar mass of H₃PO₄ is 97.99 g/mol.
3.35 g × 1 mol/97.99 g = 0.0342 mol
Step 3: Convert "V" to liters
We will use the conversion factor 1 L = 1000 mL.
200 mL × 1 L/1000 mL = 0.200 L
Step 4: Calculate the molarity of the solution
We will use the definition of molarity.
M = moles of solute / liters of solution
M = 0.0342 mol/0.200 L = 0.171 M
Question 6 of 10
What is ethane?
A. An alkane
B. An alkene
C. A polymer
D. An alkyne
Answer:
An Alkane
Explanation:
Formula of ethane is CH3-CH3
Answer:
Ethane is the second member of
An alkane
What is the Molarity of a 2 liter solution containing 43.55 grams of K2504?
Answer:
M = 0.125 M
Explanation:
Given data:
Molarity = ?
Volume of solution = 2 L
Mass of K₂SO₄ = 43.55 g
Solution;
Molarity is used to describe the concentration of solution. It tells how many moles are dissolve in per litter of solution.
Formula:
Molarity = number of moles of solute / L of solution
Number of moles of solute:
Number of moles = mass/molar mass
Number of moles = 43.55 g / 174.26 g/mol
Number of moles = 0.25 mol
Molarity:
M = 0.25 mol / 2 L
M = 0.125 M
In addition to liquid precipitation, which are present when freezing rain occurs?
ice pellets
snowflakes
cold surfaces
warm temperatures
Answer:
I believe the correct answer is cold surfaces.
Explanation:
Answer:
C
Explanation:
What mass of water in grams will fill a tank 126cm long, 47 cm wide, and 13 cm high
Answer:
Mass = 76986 g
Explanation:
Given data:
Dimensions of tank = 126 cm× 47 cm× 13 cm
Mass of water required to filled = ?
Solution:
First of all we will calculate the volume of tank which is equal to the volume of water required to fill it.
Volume = length ×height ×width
Volume = 126 cm × 13 cm× 47 cm
Volume = 76986 cm³
Mass of water:
Mass = density × volume
density of water is 1 g/cm³
Mass = 1 g/cm³× 76986 cm³
Mass = 76986 g
What is the main type of energy conversion that happens to a ball thrown in
the air as it goes up?
A. Kinetic energy to gravitational potential energy
B. Gravitational potential energy to kinetic energy
C. Chemical potential energy to kinetic energy
D. Kinetic energy to chemical potential energy
Calculate the percent composition (percent by mass of each element) of NH4Cl.
Round to the nearest ONES place ((example: 12.34% = 12%))
Answer:
[tex]\%N=26.2\%\\\\\%H=7.5\%\\\\\%Cl=66.3\%[/tex]
Explanation:
Hello!
In this case, since the calculation of the percent composition of an element in a chemical compound is computing considering its atomic mass, subscript in the formula and molecular mass of the compound it is; for nitrogen, hydrogen and chlorine we have that ammonium chloride has a molar mass of 53.49 g/mol so the percent compositions are:
[tex]\%N=\frac{14.01*1}{53.49}*100\% =26.2\%\\\\\%H=\frac{1.01*4}{53.49}*100\% =7.5\%\\\\\%Cl=\frac{35.45*1}{53.49}*100\% =66.3\%[/tex]
Best regards!
If 9.5 × 10²⁵ molecules of CO₂ are produced in a combustion reaction, what is the mass in kg of CO₂ that is produced?
Answer:
6.9428 kg of CO2
Explanation:
1) Use Avogadro's number that states 1 mole = 6.022 x 10^23 particles. Convert 9.5 x 10^25 molecules into moles.
9.5 x 10^25 CO2 molecules[tex]x\frac{1 mole CO2}{6.022 x 10^23}[/tex] = 157.75 moles CO2
2) Convert 157.75 moles of CO2 into grams. CO2's molar mass is 44.01g.
[tex]157.75moles CO2[/tex] [tex]x \frac{44.01g/mol}{1 mole CO2}[/tex] = 6942.79g
3) Convert 6942.79 grams into kilograms (divide by 1000):
6.9428 kg
Use this equation for the next question:
2NaOH + H2SO4 ® Na2SO4 + 2H20
If a reaction produces 0.75 moles Na2SO4, how many moles of NaOH were used?
0.75 moles NaOH
2 moles NaOH
.375 moles NaOH
1.5 moles NaOH
If the caffeine concentration in a particular brand of soda is 2.57 mg/oz, drinking how many cans of soda would be lethal
The lethal dose and how ounces of soda in a can of soda is not given, however, the standard lethal dose and volume of soda are given as below:
Lethal dose: 10 gm of caffeine
The volume of soda per can = 12oz/can
Answer:
The correct answer is - 324.254 cans or round up to 325 cans. Ans.
Explanation:
Given:
2.57 mg caffeine / 1oz
12oz / 1can
Lethal dose: 10.0g or 10,000mg of caffeine
Solution:
Caffeine per soda can = (2.57 mg caffeine / 1oz) * (12oz / 1can) = 30.84 mg caffeine / 1can.
lethal dose would be in =
(10,000mg caffeine) * (1can / 30.84 mg caffeine) = 324.254 cans or round up to 325 cans. Ans.
What produces the magnetic force of an electromagnet?
O magnetic fields passing through the device
O static charged particles on the wire
O movement of charged particles through the wire
O positive and negative charges repelling each other
Answer:
movement of charged particles through the wire .
Explanation:
When electricity is passed through the wire of electromagnet , moving electrons of the wire produces magnetic field . This magnetic field in increased due to high permeability of soft iron of the electromagnet . It is this magnetic field which creates magnetic force .
A clone has _________ chromosomes as its parent.
A. Half the number of
B. The same exact
C. double the number of
D. half of the same
Answer:
B. The same exact
Explanation:
I think B because in order to be a clone of your parent you have to have the exact same DNA and chromosomes.
Hope this helps :D
A clone has the same exact chromosomes as its parent.
CLONING:
Cloning is a genetic procedure in which identical copies of a cell or organism is made. Cloning can be done naturally or artificially, however, it follows the process of mitosis. In cloning, the genetic content of a parent cell is used as a template to replicate another cell or organism. Examples of cloning are biological twins, vegetative reproduction in plants etc. Therefore, a clone has the same exact chromosomes as its parent.Learn more at: https://brainly.com/question/12483409?referrer=searchResults