Help please Cu + S CuS

Identify the NMR term that corresponds to each description.

balandron [24]

Answer:

A- upfield

B- down field

C- splitting

D- chemical shift

E- integration

Explanation:

NMR is a spectroscopic technique commonly used to observe the magnetic fields around the nucleus of atoms in a compound under investigation.

A chemical shift is the difference in parts per million (ppm) between the resonance frequency of the observed protons in the compound under study and that of the tetramethylsilane (TMS) (the reference compound in NMR with a chemical shift of zero ppm because all protons in the compound are equivalent).

If signals appear close to the reference signal, the signals are said to appear upfield. If the signals appear far away from the reference, they are said to appear down field.

The presence of protons cause splitting of peaks to the magnitude of n+1. n is the number of neighboring protons. Splitting refers to the appearance of multiple peaks for a single nucleus due to neighboring nuclei.

The area of a signal that corresponds to the number of nuclei at that frequency is called the integration.

4 0

3 years ago

) Do you think the pH of 1,0 M tri-methyl ammonium (CH3)3NH+, pKa = 9.80, will be higher or lower than that of 1.0 M phenol, C6H

Elanso [62]

Answer:

1. The pH of 1.0 M trimethyl ammonium (pH = 1.01) is lower than the pH of 0.1 M phenol (5.00).

2. The difference in pH values is 4.95.

Explanation:

1. The pH of a compound can be found using the following equation:

$pH = -log([H_{3}O^{+}])$

First, we need to find [H₃O⁺] for trimethyl ammonium and for phenol.

Trimethyl ammonium:

We can calculate [H₃O⁺] using the Ka as follows:

(CH₃)₃NH⁺ + H₂O → (CH₃)₃N + H₃O⁺

1.0 - x x x

$Ka = \frac{[(CH_{3})_{3}N][H_{3}O^{+}]}{[(CH_{3})_{3}NH^{+}]}$

$10^{-pKa} = \frac{x*x}{1.0 - x}$

$10^{-9.80}(1.0 - x) - x^{2} = 0$

By solving the above equation for x we have:

x = 0.097 = [H₃O⁺]

$pH = -log([H_{3}O^{+}]) = -log(0.097) = 1.01$

Phenol:

C₆H₅OH + H₂O → C₆H₅O⁻ + H₃O⁺

1.0 - x x x

$Ka = \frac{[C_{6}H_{5}O^{-}][H_{3}O^{+}]}{[C_{6}H_{5}OH]}$

$10^{-10} = \frac{x^{2}}{1.0 - x}$

$1.0 \cdot 10^{-10}(1.0 - x) - x^{2} = 0$

Solving the above equation for x we have:

x = 9.96x10⁻⁶ = [H₃O⁺]

$pH = -log([H_{3}O^{+}]) = -log(9.99 \cdot 10^{-6}) = 5.00$

Hence, the pH of 1.0 M trimethyl ammonium is lower than the pH of 0.1 M phenol.

2. The difference in pH values for the two acids is:

$\Delta pH = pH_{C_{6}H_{5}OH} - pH_{(CH_{3})_{3}NH^{+}} = 5.00 - 1.01 = 4.95$

Therefore, the difference in pH values is 4.95.

I hope it helps you!

7 0

3 years ago

For work to be done on an object:

Mazyrski [523]

Answer:

The object has to move a distance when a force is applied to it

Explanation:

For work to be done on a body the force applied must move the body through a particular distance.

Work done = Force x distance

If no distance is moved by the force, no work is done.

Also, the angle between the force and the distance must be 0 to do the maximum work on the body.

8 0

3 years ago

.an open flask contains 0.200 mol of air. atmospheric pressure is 745 mmhg and room temperature is 68˚f. how many moles are pres

aleksklad [387]

0.219 moles moles are present in the flask when the pressure is 1.10 atm and the temperature is 33˚c.

What is ideal gas constant ?

The ideal gas constant is calculated to be 8.314J/K⋅ mol when the pressure is in kPa.
The ideal gas law is a single equation which relates the pressure, volume, temperature, and number of moles of an ideal gas.
The combined gas law relates pressure, volume, and temperature of a gas.

We simple use this formula-

The basic formula is PV = nRT where. P = Pressure in atmospheres (atm) V = Volume in Liters (L) n = of moles (mol) R = the Ideal Gas Law Constant.

68F = 298.15K

V = nRT/P = 0.2 * 0.08206 * 298.15K / (745/760) = 4.992Liters

n = PV/RT = 1.1atm*4.992L/(0.08206Latm/molK * 306K)

n = 0.219 moles

Therefore, 0.219 moles moles are present in the flask when the pressure is 1.10 atm and the temperature is 33˚c.

Learn more about ideal gas constant

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4 0

2 years ago

A woman weighing 450 Newtons sits on the floor. She exerts a force on the floor of

ANEK [815]

Answer: let me figure it out rlly quick

Explanation:

4 0

3 years ago