Answer:
d. 3 signals: a singlet, a doublet, and a septet
Explanation:
In this case, we can start with the structure of 
. When we draw the molecule we will obtain <u>2-methoxypropane</u> (see figure 1).
In 2-methoxypropane we will have three signals. The signal for the 
groups in the left, the 
and the in the right. Lets analyse each one:
-) in the right
In this carbon, we dont have any hydrogen as neighbors. Therfore we will have <u>singlet</u> signal in this carbon.
-)
In this case, we have 6 hydrogen neighbors ( the two methyl groups in the left). So, if we follow the <u>n + 1 rule</u> (where n is the amount of hydrogen neighbors):
For this carbon we will have a <u>septet</u>.
-) in the left
In this case we have only 1 hydrogen neighbor (the hydrogen in
). So, if we use the n+1 rule we will have:
We will have a doublet
With all this in mind the answer would be:
<u>d. 3 signals: a singlet, a doublet, and a septet
</u>
<u />
See figure 2 to further explanations
Answer:
The change in internal energy is - 1.19 kJ
Explanation:
<u>Step 1:</u> Data given
Heat released = 3.5 kJ
Volume calorimeter = 0.200 L
Heat release results in a 7.32 °C
Temperature rise for the next experiment = 2.49 °C
<u>Step 2:</u> Calculate Ccalorimeter
Qcal = ccal * ΔT ⇒ 3.50 kJ = Ccal *7.32 °C
Ccal = 3.50 kJ /7.32 °C = 0.478 kJ/°C
<u>Step 3:</u> Calculate energy released
Qcal = 0.478 kJ/°C *2.49 °C = 1.19 kJ
<u>Step 4:</u> Calculate change in internal energy
ΔU = Q + W W = 0 (no expansion)
Qreac = -Qcal = - 1.19 kJ
ΔU = - 1.19 kJ
The change in internal energy is - 1.19 kJ
Answer:
The nuclei of most atoms also contain neutrons . The masses of subatomic particles are very tiny. ... Since the nucleus contains protons and neutrons, most of the mass of an atom is concentrated in its nucleus. Protons and electrons have electrical charges that are equal and opposite.
Metals are elements that are generally shiny when smooth and clean
Answer:
31395 J
Explanation:
Given data:
mass of water = 150 g
Initial temperature = 25 °C
Final temperature = 75 °C
Energy absorbed = ?
Solution:
Formula:
q = m . c . ΔT
we know that specific heat of water is 4.186 J/g.°C
ΔT = final temperature - initial temperature
ΔT = 75 °C - 25 °C
ΔT = 50 °C
now we will put the values in formula
q = m . c . ΔT
q = 150 g × 4.186 J/g.°C × 50 °C
q = 31395 J
so, 150 g of water need to absorb 31395 J of energy to raise the temperature from 25°C to 75 °C .
