First, we write the half equations for the reduction of the chemical species present:
Cu⁺² + 2e → Cu; E° = 0.34 V
Ni⁺² + 2e → Ni; E° = - 0.23 V
In order to determine the potential of the cell, we find the difference between the two values. For this:
E(cell) = 0.34 - (-0.23)
E(cell) = 0.57 V
The second option is correct. (The difference in values is due to different values in literature, and it is negligible)
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
We can use the ideal gas law equation to find the volume of the gas.
PV = nRT
P - pressure - 400 kPa
V - volume
n - number of moles - 4.00 mol
R - universal gas constant - 8.314 Jmol⁻¹K⁻¹
T - temperature - 300.0 K
substituting these values in the equation
400 000 Pa x V = 4.00 mol x 8.314 Jmol⁻¹K⁻¹ x 300.0 K
V = 24.9 dm³
Volume is 24.9 dm³
Explanation:
You may not realise it, but you come across aldehydes and ketones many times a day. Take cakes and biscuits, for example. Their golden, caramelised crust is formed thanks to the Mailliard reaction. This is a process that occurs at temperatures above 140° C, when sugars with the carbonyl group in foods react with nucleophilic amino acids to create new and complex flavours and aromas.
Another example is formaldehyde. Correctly known as methanal, it is the most common aldehyde in industry. It has multiple uses, such as in tanning and embalming, or as a fungicide. However, we can also react it with different molecules to make a variety of more useful compounds. These include polymers, adhesives and precursors to explosives. But how do aldehydes and ketones react, and why?You should remember from Aldehydes and Ketones that they both contain the carbonyl functional group , . This is a carbon atom joined to an oxygen atom by a double bond. Let's take a closer look at it.
If we compare the electronegativities of carbon and oxygen, we can see that oxygen is a lot more electronegative than carbon.
