Answer:
a. 750Hz, b. 4.0ppm, c. 600Hz
Explanation:
The Downfield Shift (Hz) is given by the formula
Downfield Shift (Hz) = Chemical Shift (ppm) x Spectrometer Frequency (Hz)
Using the above formula we can solve all three parts easily
a. fspec = 300 MHz, Chem. Shift = 2.5ppm, 1MHz = 10⁶ Hz, 1ppm (parts per million) = 10⁻⁶
Downfield Shift (Hz) = 2.5ppm x 300MHz x (1Hz/10⁶MHz) x (10⁻⁶/1ppm)
Downfield Shift = 750 Hz
The signal is at 750Hz Downfield from TMS
b. Downfield Shift = 1200 Hz, Chemical Shift = ?
Chemical Shift = Downfield shift/Spectrometer Frequency
Chemical Shift = (1200Hz/300MHz) x (1ppm/10⁻⁶) = 4.0 ppm
The signal comes at 4.0 ppm
c. Separation of 2ppm, Downfield Shift = ?
Downfield Shift (Hz) = 2(ppm) x 300 (MHz) x (1Hz/10⁶MHz) x (10⁻⁶/1ppm) = 600 Hz
The two peaks are separated by 600Hz
Answer:
25.2°C
Explanation:
Given parameters:
Energy applied to the water = 1000J
Mass of water = 50g
Final temperature = 30°C
Unknown:
Initial temperature = ?
Solution:
To solve this problem, we use the expression below:
H = m c Ф
H is the energy absorbed
m is the mass
c is the specific heat capacity
Ф is the change in temperature
1000 = 50 x 4.184 x (30 - initial temperature )
1000 = 209.2(30 - initial temperature)
4.78 = 30 - initial temperature
4.78 - 30 = - initial temperature
Initial temperature = 25.2°C
Answer:
yh
Explanation:
welcome.This place is for learning
Answer:
42 19 K→42 20 Ca+e−
Explanation:
Naturally-occurring potassium atoms have a weighted average atomic mass of 39.10 (as seen on most modern versions of the periodic table.) Each potassium atom contains 19 protons p+ and thus an average potassium atom contains about 39.10−19≈20 neutrons n0.
This particular isotope of potassium-42 contains 42 nucleons (i.e., protons and neutrons, combined;) Like other isotopes of potassium 19 out of these nucleons are protons; the rest 42−19=23 are therefore neutrons.
Answer:
MgBr(aq) + (NH4)3PO4(aq) -------> NH4Br(aq) + Mg3(PO4)2(s)
Explanation:
