Please help with my Chem101 hw

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.

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.

A cleaning solution with an OH⁻ concentration of 2.5 × 10⁻⁴ mol/L, has a pH of 10.4 and is basic (options b and c).

The hydroxide ion concentration is 2.5 × 10⁻⁴ mol/L.

pOH = -log [OH⁻] = log (2.5 × 10⁻⁴) = 3.6

We will use the following expression.

pH + pOH = 14

pH = 14 - pOH = 14 - 3.6 = 10.4

Since pH > 7, the solution is basic.

A cleaning solution with an OH⁻ concentration of 2.5 × 10⁻⁴ mol/L, has a pH of 10.4 and is basic (options b and c).

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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.

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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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.

Answer:

It will release H+ in water.

Explanation:

Answer:

your welcome

Explanation:

Answer:

72.6 mL

Explanation:

A quick way to solve this titration problem when you have a monoprotic acid is to use the Dilution equation, M1V1=M2V2.

.589(x)=.821(52.1)

X=72.6 mL

0.4100 g - Rounding to four significant figures retains trailing zeros after the decimal point when followed by a non-zero digit.

Option (1) is correct.

In scientific notation, significant figures are digits that carry meaningful information about the precision of a measurement. When rounding a number to four significant figures, we consider the digits up to the fourth digit from the left (including trailing zeros after the decimal point).

In the given measurement, 0.41006 gram, we start counting from the left:

The first significant figure is "4."

The second significant figure is "1."

The third significant figure is "0."

The fourth significant figure is "0."

The fifth digit "6" is beyond the fourth significant figure, so we ignore it when rounding.

Since the fourth significant figure is "0," and it's followed by a digit greater than or equal to 5 (in this case, "6"), we round up the last significant figure. Hence, the measurement rounded to four significant figures is 0.4100 grams (option 1).

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Answer:

Thickness of foil = 0.004mm

Explanation:

V= length x width x height (height can also be known as the thickness 't')

0.5345=10.0 x (1.25÷10) x t

t=0.5345/10.0 x 12.5

t=0.004276mm

t=0.004mm

Answer:

from the ideal gas law, P2 /P1 = T2 /T1 for the same volume and quantity of gas. P2 = (758 mmHg) (45 +273 K) / (15 +273K) = 837 mmHg.

Explanation:

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

Answer:

1. yes

2. yes

3. no

sorry if I am wrong but hope this helps

Answer:

27.3 L

Explanation:

Reaction

Solving

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

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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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

Answer:

a. 67

Explanation:

3mol O2 = 2mol O3

1mol O2 = 2/3 mol O3

100g = 2/3 × 100 = 67

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.

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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Answer:

consume other organisms for energy

Answer:

consume other organisms for energy

Explanation: .....

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!

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 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]

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

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.

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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Answer:

Tangible

Explanation:

Tangible alone means it is "perceptible by touch," meaning you physically observe the object with your sense of touch.

Having tangible motivation is like working for money or a trophy.

Answer:

The point of contact between the skates and the ice.

Explanation:

It's obvious because friction is the contact between two surfaces.

Answer:

D. As time goes on, reactant and product concentration become balanced.

Explanation:

I believe this is correct.

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