Answer:
a.)
To warm the liquid from 35°C to 78°C:
(2.3 J/g-K) x (42.0 g) x (78 - 35) = 4154 J
To vaporize the liquid at 78°C:
(38.56 kJ/mol) x (42.0 g C2H5OH / 46.06867 g C2H5OH/mol) = 35.154 kJ
Total:
4.154 kJ + 35.154 kJ = 39.3 kJ
b.)
To warm the solid from -155°C to -114°C:
(0.97 J/g-K) x (42.0 g) x (-114°C - (-155°C)) = 1670 J
To melt the solid at -114°C:
(5.02 kJ/mol) x (42.0 g C2H5OH / 46.06867 g C2H5OH/mol) = 4.5766 kJ
To warm the liquid from -114°C to 78°C:
(2.3 J/g-K) x (42.0 g) x (78 - (-114)) = 18547 J
To vaporize the liquid at 78°C:
35.154 kJ (as in part a.)
Total:
1.670 kJ + 4.5766 kJ + 18.547 kJ + 35.154 kJ = 59.9 kJ
Explanation:
For the basic solution:
11.2 = -log[H+]
[H+] = 6.31 x 10⁻¹²
For the acidic solution:
2.4 = -log[H+]
[H+] = 3.98 x 10⁻³
The difference:
3.98 x 10⁻³ - 6.31 x 10⁻¹²
≈ 4.0 x 10⁻³
The answer is B
Mixture. Mixtures can be both heterogeneous and homogeneous. Heterogeneous mixtures are mixtures that don't have a fixed composition, meaning that if you take smaller samples from two different parts of a larger sample, the ratios of the substances will differ.
Answer:
The CH₃ carbon atom has tetrahedral geometry and the nitrile carbon atom has linear geometry
Explanation:
According to VSEPR theory, in an acetonitrile:
The outer carbon atom CH₃, which is connected to three hydrogen atoms and one central carbon atom, has 4 bond pairs of electrons and zero lone pair. Therefore, outer carbon atom CH₃ has a TETRAHEDRAL geometry.
The nitrile carbon atom (C≡N), which forms a single bond with the outer CH₃ carbon atom and triple bond with the nitrogen atom, has two bond pairs and zero lone pairs.
Therefore, nitrile carbon atom has a LINEAR geometry.
Volume of base(NaOH)= Vb =6 mL
Concentration of base(NaOH)= Mb =3 M
Volume of acid(HCl)= Va =9 mL
Concentration of acid(HCl)= Ma = ?
Now,
Ma*Va = Mb*Vb
Ma*(9) = (3)*(6)
Ma= 2 M
