Answer:
Butan-2-one
Explanation:
1. 1700 cm⁻¹
A strong peak near 1700 cm⁻¹ is almost certainly a carbonyl (C=O) group.
2. Triplet-quartet
A triplet-quartet pattern indicates an ethyl group.
The 2H quartet is a CH₂ adjacent to a CH₃. The peak normally occurs at δ 1.3, but it is shifted 1.2 ppm downfield to δ 2.47 by an adjacent C=O group.
The 3H triplet at δ 1.05 is the methyl group. It, too, is shifted downfield from its normal position at δ 0.9. The effect is smaller, because the methyl group is further from the carbonyl.
3. 3H(s) at δ 2.13
This indicates a CH₃ group with no adjacent hydrogen atoms.
It is shifted 0.8 ppm downfield to δ 2.13 by the adjacent C=O group.
4. Identification
The identified pieces are CH₃CH₂-, -(CO)-, and -CH₃. There is only one way to put them together: CH₃CH₂-(C=O)-CH₃.
The compound is butan-2-one.
If you melt and cool silicon dioxide under very special conditions
<span>in the laboratory we can grow a single </span>crystalline<span> form of </span>
<span>silicon dioxide that we call quartz. In quartz crystals all of </span>
<span>the molecules are aligned and bonded together in a regular three </span>
<span>dimensional tetrahedral structure forming a very hard, transparent </span>
<span>material with special electronic properties. </span>
The atoms undergo chemical changes.
New substances may be a product of the reaction.
Answer:
36365.4 Joules
Explanation:
The quantity of Heat Energy (Q) released on cooling a heated substance depends on its Mass (M), specific heat capacity (C), and change in temperature (Φ)
Thus, Q = MCΦ
Since, M = 45.4 g
C = 3.56 J/g°C,
Φ = 250°C - 25°C = 225°C
Q = 45.4g x 3.56J/g°C x 225°C
Q= 36365.4 Joules
Thus, 36365.4 Joules of heat energy is released when the lithium is cooled.
Answer is C.
Converting temperatures to degrees K: 33 degrees C = 306 K and -55 = 218 degrees K.
By the ideal gas law:-
760 * 0.50 / 306 = P * 0.10 / 218
P = 760 * 0.50 * 218 / 306 * 0.10
= 2700 mm Hg answer
