Answer: Because percent solutions can be expressed in three different ways, it is imperative that the type of percent solution be explicitly stated. If this information is not provided, the end user is left to "guess" whether w/v %, w/w %, or v/v % was used. Each percent solution is appropriate for a number of different applications. For example, commercial aqueous reagents, such as concentrated acids and bases, are typically expressed as weight/weight % solutions. For example, commercially available concentrated hydrochloric acid (HCl) is 37% by weight (w/w %). On the other hand, many dilute solutions used for biological research are expressed as weight/volume % (e.g., 1% sodium dodecyl sulfate, SDS). Volume/volume % solutes are also common, and are used when pure solutes in liquid form are used. For example, a 70 % (v/v) solution of ethanol can be prepared by dissolving 70 mL of 100% (i.e., 200 proof) ethanol in a total solution volume of 100 mL.
How many grams of KBr are dissolved in 92.7 mL of a 0.955 M solution? Show your work.
Answer:
10.5g of KBr
Explanation:
molarity = moles of solute / litres of solution
we are given the volume of the solution in milliliters but the formula uses litres so we have to convert
to convert to liters we divide the number of milliliters by 1000 ( because 1 liter has 1000 milliliters. )
so liters of solution = 92.7/1000 = 0.0927 L
we can now plug in what we are given and solve for moles of solute
recall molarity = moles of solute / litres of solution
molarity = 0.955M and liters of solution = 0.0927L
so [tex]0.955M=\frac{moles.of.solute}{0.0927L}[/tex]
multiply both sides by 0.0927
we're left with moles of solute = 0.0885285 moles
Finally we must convert moles to grams
Molar mass of KBr = 39.0983 + 79.904 = g/mol
Using dimensional analysis we get [tex]\frac{0.0885285molKBr}{} *\frac{119.002g}{1molKBr}[/tex]
the mol KBr cancel out on both sides and we get [tex]0.0885285 *119.002g[/tex] which is equal to 10.5g (rounded)
So we can conclude that 10.5g of KBr is dissolved in 92.7mL of a 0.955M solution.
What are the substance that causes environment effect?
Answer:
Common environmental chemical pollutants include pesticides and herbicides, volatile organics (VOCs) such as benzene, toluene; and chloroform, heavy metals such as lead, mercury, and arsenic; air contaminants such as carbon monoxide, ozone, particulate matter (PM), and second hand smoke; and persistent organic pollutants, such as the dioxins, PCBs, and DDT. Environmental chemicals can cause a broad spectrum of effects, which depend not only on route of exposure and dose, but on the susceptibility of the recipient of the pollution
The diagram displays the concentration of products (blue) and reactants (red) over time for a chemical reaction.
Which statement is true?
Reactant concentration is always decreasing.
Product concentration is always increasing.
Reactant and product concentrations are never equal.
As time goes on, reactant and product concentrations become balanced.
Answer:
D. As time goes on, reactant and product concentration become balanced.
Explanation:
I believe this is correct.
What volume of it must be diluted with water to obtain 500cm 3 of 0.01 molar solution. If the stock solution is 1.0 M?
Answer:
5 cc
Explanation:
.01 M * 500/1000 = .005 M needed
1.0 M * x .005 M
x =.005 liter 5 cc
5cc of 1M dilute to 500 cc
The concentration or volume of a solution can be determined from the molarity and volume of the second solution. The volume the solution of 1 M to prepare 500cm³ of 0.01 molar solution is 5 molar.
What is molarity?Molarity of a solution is its concentration in terms of number of moles per unit volume. Molarity depends on the temperature and amount of solute and solvent as well.
If a solution have M1 molarity and V1 volume and a second solution have M2 volume and V2 volume then the relation between these quantities is written as follows:
M1V1 = M2V2
Given that solution to be prepared has the concentration of 0.01 M and volume of 500 cm³. Then the volume of stock solution with 1.0 M concentration is calculated as follows:
500cm³ × 0.01 M = 1.0 M × V2
V2 = (500cm3 × 0.01 M )/1.0 M
= 5 cm³
Hence, the volume of stock solution is 5 cm³ required for the preparation of 500cm³ of 0.01 molar solution.
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What’s a bond when it come to chemical structure
Answer:An electron positioned between two nuclei will be attracted to both of them, and the nuclei will be attracted toward electrons in this position. This attraction constitutes the chemical bond.
Explanation:good luck
How many moles are in 80.0g of sodium chloride (NaCl)
Answer:
1.37 mol NaCl
Explanation:
Hi!
For this one, you are given a mass (in grams) of NaCl, 80.0.
To convert this to moles, you have to do a mass-to-mole calculation, where you use the molar mass of NaCl.
Na's m.m. is 22.99 g/mol
Cl's m.m. is 35.45 g/mol
1(22.99 g/mol) + 1(35.45 g/mol) = 58.44 g/mol => here is the molar mass of NaCl.
Here's the setup for the conversion:
g(mol/g) - we are flipping g/mol to mol/g to get mol on top (since we are looking for the # of mol) and g on the bottom to cancel out the g unit.
80.0 g NaCl(1 mol NaCl/58.44 g NaCl) = 80.0 / 58.44 = 1.37 mol NaCl.
I hope this helped!
Which choice has the least thermal energy
I need answers please
Answer:
It will release H+ in water.
Explanation:
Acid releases hydrogen ionsAlkaline is slippy such as soap, shampoo which is slippery contains alkaline.Alkaline dissociates to release OH- ions in water.In an addition reaction to an alkene, the pie bond plays the role of ?
Answer:
The pi bond is electron rich and takes the role of the nucleophile seeking out an electrophile with its full or partial positive charge. Using a general molecule X-Y as the electrophile reacting with ethene, the atoms 'X' and 'Y' are added to the carbon chain across the vinylic carbons as shown below.
Explanation:
hope this helps
Explain why the chemical properties of Mg 24 12 and Mg 26 12 are the same
1. In Eunice Foote's experiment comparing how different kinds of gases trap heat, a glass
cylinder filled with warmed the most.
a humid air
b. dry air
C. common air
d. carbon dioxide
Answer: D carbon dioxide
Explanation:
usually, carbon dioxide is the best gas for trapping heat. Our atmosphere has carbon dioxide in it to keep the heat of the Sun close so we can live. But too much of this gas as well as other greenhouse gases can cause the Earth to heat up more.
Calculate the mass of NaOH required to make 0.40 L of a 0.50 M solution
Answer:
8 gm
Explanation:
NaOH molar weight = 22.989 + 15.999 + 1.008 = 39.996 gm
.5 M would contain 1/2 of this per liter = 19.998 gm
now you only want 400/1000 of a liter = 7.9992 gm ~ 8gm
what is the formula for carbon?
The structural formula of carbon is as shown below. Carbon is a nonmetallic and tetravalent compound that can accommodate 4 electrons to form a covalent bond. It has the capacity to establish bonds easily with other atoms and with other carbon atoms too, carbon is competent of establishing multiple stable covalent bonds with suitable multivalent atoms.
Chemical formula = [tex]C[/tex]
In the reaction 3 O2 --> 2 O3, how many grams of O3 will be formed from the reaction of 100 g of O2?
a. 67 g
b. 133 g
c. 50 g
d. 100 g
Answer:
a. 67
Explanation:
3mol O2 = 2mol O3
1mol O2 = 2/3 mol O3
100g = 2/3 × 100 = 67
H. Nitrogen gas and hydrogen gas combine to produce ammonia gas (NH3).
What volume of hydrogen gas at 25°C and 735 mm is required for the
complete reaction of 10.0g of nitrogen?
Answer:
27.3 L
Explanation:
Reaction
N₂ (g) + 3H₂ (g) ⇒ 2NH₃ (g)This is the basic reaction at STPSolving
10 g N₂ x 1 mol NH₃/28 g N₂ x 3 mol H₂/1 mole N₂⇒ 1.07 mol H₂V = nRT/P [From Ideal Gas Equation]V = 1.07 x 62.36 x 298 K / 735V = 27.3 L27.3 L. N₂ (g) + 3H₂ (g) ⇒ 2NH₃ (g). 10 g N₂ x 1 mol NH₃/28 g N₂ x 3 mol H₂/1 mole N₂ ⇒ 1.07 mol H₂. V = nRT/P [From Ideal Gas Equation], V = 1.07 x 62.36 x 298 K / 735. V = 27.3 L
What is Nitrogen gas?A non-flammable atmospheric gas called nitrogen makes about 78% of the earth's atmosphere.
Nitrogen is prized for its inert qualities when it is gaseous because it replaces air, which lessens or stops items from oxidizing. Additionally, it serves as a laser cutting assist gas.
Nitrogen is a perfect gas for cryogenic cooling and freezing because of the incredibly low temperatures at which it exists in its liquid state. Almost any industry can use nitrogen to increase yields and maximize performance. It makes it possible to utilize and store flammables safely while also preventing the explosion of combustibles.
Therefore, 27.3 L. N₂ (g) + 3H₂ (g) ⇒ 2NH₃ (g). 10 g N₂ x 1 mol NH₃/28 g N₂ x 3 mol H₂/1 mole N₂ ⇒ 1.07 mol H₂. V = nRT/P [From Ideal Gas Equation], V = 1.07 x 62.36 x 298 K / 735. V = 27.3 L.
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HELP!
How many moles of a solute would 3 liters of a 2-molar solution contain?
The number of moles of a solute that 3 liters of a 2-molar solution would contain is 6 moles. Details about number of moles can be found below.
How to calculate number of moles?The number of moles of a substance can be calculated using the following formula:
Molarity = no of moles ÷ volume
According to this question, there are 3 liters of a 2-molar solution. The number of moles can be calculated as follows:
no of moles = 3L × 2M
no of moles = 6 moles
Therefore, the number of moles of a solute that 3 liters of a 2-molar solution would contain is 6 moles.
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how do you interpret this IR spectrum
First if you have a data sheet you would compare the four peaks that are denoted by a,b,c and d and see if the number in which the peak falls alligns with a bond type present in the moecule. IR spectroscopy is used quite alot in organc chemistry so using my data sheet I'd assume that;
Peak D, likely represents a C-O bond (found in wavenumer range 1000-1300)
Peak C, likely represents a C-H bending vibrations (with wavenumber range 1400-1500)
Peak B, is likely a C=C bond, (with wavenumber range of 1620-1680
Peak A, is likely a C=O bond, (with wavenumber range of 1680-1750)
From here you could predict some possible molecules that the IR spectrum alligns with ie any molecules that are composed of C-H, C-O, C=O and C=C bonds, like an ester with an unsaturated carbon chain.
N₂O(g) + 3 H₂(g) N₂H4(1) + H₂O(1) AH = -317 kJ/mol
and standard heats of formation:
N₂O(g) +82.1 kJ/mol
H₂O(1) 285.8 kJ/mol.
What is the standard heat of formation of hydrazine (N₂H4(1)) ?
Select one:
O a. 50.9 kJ/mol
O b. - 520.7 kJ/mol
O c. 113.3 kJ/mol
O d. - 50.9 kJ/mol
e. 113.3 kJ/mol
Answer:
A
Explanation:
Recall that ΔH is the sum of the heats of formation of the products minus the heat of formation of the reactants multiplied by their respective coefficients. That is:
[tex]\displaystyle \Delta H^\circ_{rxn} = \sum \Delta H^\circ_{f} \left(\text{Products}\right) - \sum \Delta H^\circ_{f} \left(\text{Reactants}\right)[/tex]
Therefore, from the chemical equation, we have that:
[tex]\displaystyle \begin{aligned} (-317\text{ kJ/mol}) = \left[\Delta H^\circ_f \text{ N$_2$H$_4$} + \Delta H^\circ_f \text{ H$_2$O} \right] -\left[3 \Delta H^\circ_f \text{ H$_2$}+\Delta H^\circ_f \text{ N$_2$O}\right] \end{aligned}[/tex]
Remember that the heat of formation of pure elements (e.g. H₂) are zero. Substitute in known values and solve for hydrazine:
[tex]\displaystyle \begin{aligned} (-317\text{ kJ/mol}) & = \left[ \Delta H^\circ _f \text{ N$_2$H$_4$} + (-285.8\text{ kJ/mol})\right] -\left[ 3(0) + (82.1\text{ kJ/mol})\right] \\ \\ \Delta H^\circ _f \text{ N$_2$H$_4$} & = (-317 + 285.8 + 82.1)\text{ kJ/mol} \\ \\ & = 50.9\text{ kJ/mol} \end{aligned}[/tex]
In conclusion, our answer is A.
Which pair of formulas represents two compounds that are electrolytes?
C5H12 and CH3OH
HCl and NaOH
HCl and CH3OH
C5H12 and NaOH
The pair of formulas represents two compounds that are electrolytes are HCl & NaOH.
What are electrolytes?Electrolytes are the solutions which contains positive or negative ions in it as a result of which it conducts electricity.
C₅H₁₂ & CH₃OH are not electrolytes as they will not dissociate into their respective ions.HCl & NaOH both are electrolytes as they dissociate into their ions in the solution form.Among HCl & CH₃OH, only HCl is a electrolyte and methanol is a non electrolyte.Among C₅H₁₂ & NaOH, NaOH is a electrolyte and C₅H₁₂ is a non electrolyte.Hence pair of electrolytes are HCl & NaOH.
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If a space rover has a mass of 3900 kg on earth then what is its mass when it lands on mars?
Answer:
390, the force of gravity is 10 N on Earth, so you would divide 3900 by 10
Explanation:
The mass of the space rover will remain constant but its weight will change.
What is Mass?Mass defines the amount of matter present in any object or body. It is also a measure of body's inertia.
Given is a space rover that has a mass of 3900 kg on earth.
Mass of an object is the sum of the masses of all the individual masses of its constituents. Mass of an object always remains constant. Anywhere in the universe, the mass of body cannot change. Although, if we talk about the mass of body as its velocity approaches the speed of light, the mass of body changes according to the general relativity but that is not the case here. However, weight of the object say space rover will be different as it depends upon the acceleration due to gravity (g) on mars. At mars -
Acceleration due to gravity [g] = 3.72 m/s²
Mass of space rover [M] = 3900 Kg [remain same]
Weight of space rover [W] = Mg = 3900 x 3.72 = 14508 Kg
Therefore, the mass of the space rover will remain constant but its weight will change.
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The question is in the attached screenshot. Thanks a lot
Answer:
your welcome
Explanation:
A sound wave is traveling at 6,420 m/s and has a frequency of 600 Hz.
What is the wavelength?
10.7 mExplanation:The wavelength of a wave can be found by using the formulawherec is the speed of the wavef is the frequencyFrom the questionc = 6420 m/sf = 600 HzWe haveWe have the final answer as10.7 mHope this helps you
Which is NOT something that producers do?
Group of answer choices
consume other organisms for energy
photosynthesize
take energy from the sun and turn it into food energy
serve as food energy for many other organisms
ANSWER ASAP PLS!!!
Answer:
consume other organisms for energy
Answer:
consume other organisms for energy
Explanation: .....
Which scenario would adhere to the law of conservation of energy?
Examples of scenarios that would adhere to the law of conservation of energy are as follows:
In a loudspeaker, electrical energy is converted into sound energy.In a microphone, sound energy is converted into electrical energy.In a generator, mechanical energy is converted into electrical energyWhat is law is conservation of energy?The law of conservation of energy states that energy cannot be created nor destroyed but is conserved when it is transferred from one form to another.
The law of conservation of energy is obeyed by majority of natural and artificial systems. For example;
In a loudspeaker, electrical energy is converted into sound energy.In a microphone, sound energy is converted into electrical energy.In a generator, mechanical energy is converted into electrical energyLearn more about law of conservation of energy at: https://brainly.com/question/20971995
Answer:
Answer is D on edge 2022
Explanation:
How much more would a 20.0 gallon tank for propane
(C3H3) weigh if it was originally empty, 1 gallon = 3.8 L, but now has a
pressure of 2.4atm at a temperature of 27 Celsius?
Give your answer in grams.
Answer: 20 + 1 + 3.8 + 2.4 +27 = 54.2
Explanation: 20 gallons plus 1 gallon plus 3.8 plus 2.4 plus 27 equals to a total number of 54.2 gallons for the propane.
Bonding with intermolecular forces:
1.) is CH3I a hydrogen bonding? yes or no?
2.) is CH3I dipole-dipole interactions? Yes or no?
3.) is CH3I a london dispersion forces? Yes or no?
Answer:
1. yes
2. yes
3. no
hope this helps
sorry if I am wrong
Which type of science is the study of living things and living systems?
A. Life science
B. Physical science
C. Earth science
D. Space science
Which of the following compounds' solubility will not be affected by a low pH in solution?
O AgBr
O NICO3
O CO(OH)2
O PbF2
O Cus
The compound solubility which will not be affected by a low pH in solution is AgBr.
What is pH?pH is a measure of the acidity or basicity of any solution and according to the pH scale 0 to 6.9 shows the acidity, 7 is neutral and 7.1 to 14 shows the basicity of any solution.
AgBr is sparingly soluble in water and not soluble in acids, so if we low the pH of the solution towards the acidity its solubility not affected.NiCO₃ is a basic salt and and shows solubility in the acidic medium so change in pH will affect its solubility.Co(OH)₂ it is also a basic compound and shows its solubility in the acidic medium and get affected when change in pH takes place.PbF₂ is a strong base and also shows solubility in the acidic medium easily, so get affected when change in pH takes place.In CuS, sulphide is basic ion and whole compound shows solubility in the acidic medium and get affected when low pH of solution takes place.AgBr is not affected by a low pH in solution.
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Bonding with intermolecular forces:
1.) is C2H5CI a hydrogen bonding? yes or no?
2.) is C2H5CI dipole-dipole interactions? Yes or no?
3.) is C2H5CI a london dispersion forces? Yes or no?
Answer:
1. yes
2. yes
3. no
sorry if I am wrong but hope this helps
Where is the friction that allows the skater to complete the move that is occurring in this image?
a girl ice skating
© Wildcow / iStock 2018
The movement of her skirt through the air
The movement of her body through the air
The point of contact between the skates and the ice
The point of contact between the skates and her foot
Answer:
The point of contact between the skates and the ice.
Explanation:
It's obvious because friction is the contact between two surfaces.