Answer:
Zero
Explanation:
The complete reaction for this is as follows -
HBr + NaOH = NaBr + H2O
1 mole of NaOH reacts with 1 mole of HBr
m(HBr) = 57.4g and M(HBr) = 80.9g/mol
m(NaOH) = 16g and M(NaOH) = 40g/mol
Number of moles = m/M
Substituting the given values we get -
n(HBr) = 57.4 g/80.9 g/mol = 0.709
n(NaOH) = 16 g/40 g/mol = 0.4
n(H2O) = n(NaOH) = 0.40 mol
According to balanced equation
40 gram of NaOH reacts with 81 grams of HBr
41 gram of NaOH will react with 81/40 * 41 = 83.025 gram of HBr
We have only 57.4 g of HBr only hence, 0 HBr will be left.
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]
An element has five isotopes. Calculate the atomic mass of this element using the information below. Show all your work. Using the periodic table, identify the element this is likely to be and explain your choice. (18 pts)
A) Isotope 1 – mass: 64 amu; percent abundance: 48.89%
B) Isotope 2 – mass: 66 amu; percent abundance: 27.81%
C) Isotope 3 – mass: 67 amu; percent abundance: 4.11%
D) Isotope 4 – mass: 68 amu; percent abundance: 18.57%
E) Isotope 5 – mass: 70 amu; percent abundance: 0.62%
Answer: Sol:-
Data provided in the question is :-
Atomic mass of isotope -1 = 64 amu
Atomic mass of isotope -2 = 66 amu
Atomic mass of isotope -3 = 67 amu
Atomic mass of isotope -4 = 68 amu
Atomic mass of isotope - 5 = 70 amu
Percentage abundace of isotope - 1 = 48.89 %
Percentage abundance of isotope -2 = 27.81 %
Percentage abundance of isotope - 3 = 4.11%
Percentage abundance of isotope-4 = 18.57%
Percentage abundance of isotope - 5 = 0.62 %
Formula used :-
Average atomic mass of an element =[ {(atomic mass of isotope-1 * percentage abundance of isotope-1) + ( atomic mass of isotope-2 * percentage abundance of isotope -2) + ( atomic mass of isotope -3 * percantege abundance of isotope-3 ) + ( atomic mass of isotope-4 * percentage abundance of isotope-4) + (atomic mass of isotope-5 * percentage abundance of isotope-5)} / 100]
Calculation :-
Put all the value in the formula :-
Average atomic mass of an element = [{(64 * 48.89) + (66 * 27.81) + (67 * 4.11) + (68 * 18.57) + (70 * 0.62)} / 100] amu
= [{(3128.96) + (1835.46) +(257.37) + (1262.76) + (43.4)} / 100] amu
= {(6528.04) / 100} amu
= 65.2804 amu
Average atomic mass of an element is = 65.2804 amu
Then this mass is approximatly equal to atomic mass of zinc so this element would be zinc
atomic mass of zinc = 65.38 \approx 65.2804 amu
(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
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
Which statement gives a disadvantage of multicellular organisms?
A. They need small amounts of energy
B. They reproduce slower than unicellular organisms
C. They can perform more functions
D. Cells are able to provide support
Answer: B. They reproduce slower than unicellular organisms
Explanation:
In unicellular organisms there is a single cell which performs all the functions like digestion, respiration, and reproduction. The cell reproduce by cell division. The single parent cell divides into two identical daughter cells. But multicellular organisms exhibit multiple cells and their reproduction is complex. They reproduce by sexual mode of reproduction in which separate sex cells are produced when they fuse form zygote which is the precursor of new organism. This process is slower than that of the cell division and production of progeny by the unicellular organisms. Thus reproduction is slower in multicellular organism this is the disadvantage in multicellular organisms.
Answer:
B. they reproduce slower than unicellular organisms
Explanation:
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
Will measuring the melting point of your product tell you that your product is relatively pure?
Answer and Explanation:
Yes. The determination of melting point is used to analyze if a solid compound is pure or impure. The melting point of a pure solid product does not vary in a narrow range, whereas if impurities are present the solid melts in a broad range of temperatures. For this reason, this technique is generally used to determine the identity and purity of the products obtained in chemical reactions.
When preparing for work in the fume hood, be sure to gather all necessary tools, glassware, and chemicals _________ to minimize the number of times the hood sash is raised and lowered. Work as much as possible in the _________ of the work surface to keep the area tidy and promote air flow. If you need to step away from the experiment to obtain another item, _________ the sash during this time.
Answer:
In advance
middle
lower
Explanation:
These are the safety precautions needed when carrying out duties in the fume hood.
When planning and preparing to work in a fume hood (a locally designed area to reduce exposure to hazardous fumes). It is advisable to make all equipment readily available at your disposal in advance to reduce and minimize the raising and lowering of the hood sash at intervals.
It is also pertinent to understand that working in the middle of the work surface helps to promote the movement of air and keeps the area neat and tidy.
However, if any case where there is a need to get a new tool or equipment during the process of working in a fume hood, it is advisable to lower the sash at that point in time.
When a substance undergoes a chemical change, its identity does not change.
O True
O False
Answer:
False
Explanation:
Chemists make a distinction between two different types of changes that they study—physical changes and chemical changes. Physical changes are changes that do not alter the identity of a substance. Chemical changes are frequently harder to reverse than physical changes.
A student dissolves of aniline in of a solvent with a density of . The student notices that the volume of the solvent does not change when the aniline dissolves in it. Calculate the molarity and molality of the student's solution. Be sure each of your answer entries has the correct number of significant digits.
Answer:
Molarity: 0.21M
Molality: 0.20m
Explanation:
...dissolves 3.9g of aniline (C6H5NH2) in 200.mL of a solvent with a density of 1.05 g/mL...
To solve this question, we need to find the moles of aniline in 3.9g using its molar mass. Then, we need to find the kg and Liters of solution in order to find molarity (Moles/L solution) and molality (Moles/kg of solvent):
Moles aniline:
Molar mass:
6C: 6* 12.01g/mol = 72.06g/mol
7H: 7*1.008g/mol = 7.056g/mol
N: 1*14.007g/mol = 14.007g/mol
72.06g/mol+7.056g/mol+14.007g/mol = 93.123g/mol
Moles of 3.9g: 3.9g * (1mol / 93.123g) = 0.04188moles
Liters solution:
200mL * (1L / 1000mL) = 0.200L
kg solvent:
200mL * (1.05g/mL) * (1kg/1000g) = 0.210L
Molarity:
0.04188mol / 0.200L = 0.21M
Molality:
0.04188mol / 0.210L =0.20m
Describe the relationship between kinetic energy and the states of matter?
PLS HELP I DONT SCIENCE HELP ASAP HELP
Answer:
The kinetic molecular theory of matter states that: Matter is made up of particles that are constantly moving. All particles have energy, but the energy varies depending on the temperature the sample of matter is in. This in turn determines whether the substance exists in the solid, liquid, or gaseous state.
Explanation:
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]
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.
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.
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.
If 1.546 g of copper was used by a student at the start of the lab, and 0.732 g of copper were obtained at
the end of the series of reactions, what was the percent recovery? Briefly explain how you found your
answer.
Answer: Percent recovery is 47.34 %
Explanation:
Percent yield is defined as the ratio of experimental yiled to theoretical yield in terms of percentage.
[tex]{\text{ percent yield}}=\frac{\text{amount recovered}}{\text{total amount}}\times 100[/tex]
Putting in the values we get:
[tex]{\text{ percent yield}}=\frac{0.732}{1.546}\times 100=47.34\%[/tex]
Therefore, the percent recovery is 47.34 %
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.
Find the mass in grams of 1.38 moles of Sr
Answer:
116.78 grams.
Explanation:
1 mol of Strontium (Sr) = 87.62 grams
1.38 mol of Strontium = x
Cross Multiply
1 * x = 1.38 * 87.62
x = 116.78 grams
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
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
3.
What do we call materials
that let heat pass through
them easily?
Thermal conductors
Thermal insulators
Transparent
4.
Which of these is a good
thermal conductor?
Plastic
Wood
Steel
5.
Which of these is a good
thermal insulator?
Steel
Iron
Polystyrene
6.
To save on heating bills, do
you think the roof of a
building should be lined with...
a thermal conductor
a thermal insulator
nothing
7.
How does heat travel?
From cold things to hotter things
From hot things to colder things
Between things of the same temperature
Answer:
thermal conductors
steel
polystyrene
thermal insulator
between things of the same temp?
sorry to ask but if its ok with you, may i get brainly, i need to rank up all i need is two more, if not its fine. thank you and yours truly golden
Plz help ASAP i will give brainlists
2AgNO3 + BaCl2 + 2AgCl + Ba(NO3)2
How many grams of silver chloride are produced from 15.0 g of silver nitrate reacting with an excess of barium chloride?
A)9.44 g Agci
B)16.4 g Agci
C)12.7 g Agci
D)0 20.1 g Agci
is C5H10 ionic or covalent?
In a laboratory setting, concentrations for solutions are measured in molarity, which is the number of moles per liter (mol/L). Concentrations are often converted to more common units on the labels of household products. For a particular brand of bleach, the concentration of sodium hypochlorite (NaClO) is reported on the bottle as 7.25% by mass. The following information can thus be used to calculate the molarity of NaClO in the bleach:
• 1L of bleach has a mass of 1,100 grams.
• 7.25% of the mass of bleach is NaClO.
• 1 mol of NaClO has a mass of 74.44 grams.
What is the molarity (mol/L) of NaClO in the bleach?
A.0.097
B.0.93
C.1.07
D.79.75
Answer:
its C
Explanation:
1/74.44 * 79.75 = 1.07
The molarity (mol/L) of NaClO in the bleach, given the data is 1.07 mol/L (Option C)
What is molarity?Molarity is defined as the mole of solute per unit litre of solution. Mathematically, it can be expressed as:
Molarity = mole / Volume
How to determine the mass of NaClO in the bleachMass of bleach = 1100 gPercentage of NaClO = 7.25%Mass of NaClO = ?Mass of solute = percent × mass of solution
Mass of NaClO = 7.25% × 1100
Mass of NaClO = 0.0725 × 1100
Mass of NaClO = 79.75 g
How to determine the mole of NaClO Mass of NaClO = 79.75 gMolar mass of NaClO = 74.44 g/moleMole of NaClO =?Mole = mass / molar mass
Mole of NaClO = 79.75 / 74.44
Mole of NaClO = 1.07 mole
How to determine the molarity Mole of NaClO = 1.07 moleVolume = 1 L Molarity of NaClO =?Molarity = mole / Volume
Molarity of NaClO = 1.07 / 1
Molarity of NaClO = 1.07 mol/L
Learn more about molarity:
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Which equation shows how to solve for enthalpy of solution based on the information in tables?
Answer: B. triH sol Mgl2= -triHlat+ triHhydr Mg^2+ 2triHhydr^l-
Explanation:
Just did it and it was right
The octet rule states that atoms in molecules share electrons in such a way that each atom has a full valence shell. Determine whether each structure has the correct number of electrons and obeys the octet rule. Classify structures that have the correct number of electrons and obey the octet rule as valid, and those that do not as invalid. valid structure invalid structure
Answer:
Their must be a picture with this question so we can answer it
Explanation:
According to octet rule the bonded valence shells are completely filled. All the compounds except the first one, CH₃CH₃O is invalid since H does not obey the rule and invalid.
What is octet rule?Octet rule says that an atoms become stable when it completes its valence shell to 8 electrons or 2 electrons for K-shell. Thus bonded shells have to completely filled to be stable.
Each atom shares its electrons based on its valency. For example carbon have a valency of 4 and it forms for bonds and oxygen and sulfur have two and hydrogen forms only one bonds.
In the first compounds CH₃CH₃O, where one H forms two bonds which is not possible and invalid.
In the second compound CONH, all the atoms satisfies its valency including nitrogen having a valency of three forms three bonds. Similarly in CH₂F₂, one fluorine forms one bond and the structure is valid.
In the case of Br₂ , each bromine shares one electron with the other and complete their octet to eight electrons. In NH₃, SCO and COCl₂ all the atoms satisfies their valency and the structures are valid.
Therefore the only invalid structure is first compound, remaining all are valid.
To find more about octet rule, refer the link below:
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Your question is incomplete. But most probably your complete question was as in the uploaded image.
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
What does not affect the strength of an electromagnet?
Answer:
Unlike a permanent magnet, an electromagnet can be turned on and off using electrical current. Many variables affect the strength of this electromagnet, and there are some variables that do not affect the strength. ... Making the nail longer will not make the magnet stronger, unless you also add more turns to the coil.
electromagnet can be turned on and off using electrical current. Many variables affect the strength of this electromagnet, and there are some variables that do not affect the strength
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
Please help me thanks so much?!?!?
Answer:
color
Explanation:
Answer:
D
Explanation:
The five conditions of chemical change: color chage, formation of a precipitate, formation of a gas, odor change, temperature change and the others are just physical changes that would happen if you change containers, or let it evaporate.