Answer:
A)The characteristic frequency to look out for is 1720-1740 cm-1 (for C=O) for which will disappear in the end product but initially present in the reactant.
B)Characteristic frequency present in the infrared spectrum will be at a peak of 3300-3400 cm-1 which will be due to O-H stretch.
C)If the product is wet with water there will be no change in the infrared spectrum
Explanation:
The characteristic frequency to look out for is 1720-1740 cm-1 (for C=O) for which will disappear in the end product but initially present in the reactant.
Characteristic frequency present in the infrared spectrum will be at a peak of 3300-3400 cm-1 which will be due to O-H stretch.
If the product is wet with water there will be no change in the infrared spectrum
Answer:
0.4 * 10^-12 m
Explanation:
Frequency of the given Electromagnetic radiation is 7.50* 10^20 Hz
Speed of the electromagnetic radiation is 3*10^8 m/s
Hence wavelength is given by the formula: Speed/Frequency
Substituting the required values:
Wavelength = 3 * 10^8/7.50 * 10^20
=3/7.5 * 10^-12 = 0.4 * 10^-12 m
Hence the required wavelength of the electromagnetic radiation is 0.4*10^-12 m/s
Answer:
Cr₂S₃
Explanation:
From the question given above, the following data were obtained:
Mass of chromium (Cr) = 0.67 g
Mass of chromium sulfide = 1.2888 g
Empirical formula =?
Next, we shall determine the mass of sulphur (S) in the compound. This can be obtained as follow:
Mass of chromium (Cr) = 0.67 g
Mass of chromium sulfide = 1.2888 g
Mass of sulphur (S) =?
Mass of S = (Mass of chromium sulfide) – (Mass of Cr)
Mass of S = 1.2888 – 0.67
Mass of S = 0.6188 g
Finally, we shall determine the empirical formula of the compound. This can be obtained as follow:
Mass of Cr = 0.67 g
Mass of S = 0.6188 g
Divide by their molar mass
Cr = 0.67 / 52 = 0.013
S = 0.6188 / 32 = 0.019
Divide by the smallest
Cr = 0.013 / 0.013 = 1
S = 0.019 / 0.013 = 1.46
Multiply by 2 to express in whole number
Cr = 1 × 2 = 2
S = 1.46 × 2 = 3
Therefore, the empirical formula of the compound is Cr₂S₃
3O2 ------> 2O3
6O 6O
6 atoms of O before and after reaction.
Tell you what - the more likely scenario is that iron reacts with oxygen to form 6.2g of Fe2O3. That's the rusting of iron; I don't know if you can "un-rust" iron back into pure iron and oxygen. So we'll go with this equation:
4Fe + 3O2 --> 2Fe2O3.
Iron (Fe) is our unknown. Okay, Fe2O3, which is iron(III) oxide, has a given mass of 6.2g, and according to the Periodic Table, it's molar mass, or grams per 1 mole, is 160g/mol (56+56+16+16+16). Do a 1-step molar conversion to get about 0.03875 moles. Apply this to the molar ratio of coefficients in the balanced equation: the ratio is 2:4, or 1:2, so you will double that to 0.0775 moles of iron. Now do a 1-step molar conversion with iron's Atomic Mass to get your grams of iron: 0.0775 moles x 56 grams per mole = 4.34 grams Fe.