When KOH dissolved in ethanol, what is the intermolecular attraction between OH- ions and C2H5OH molecules

Pick the correct pair of species that can form hydrogen bond with water. (A) CH, HCOOH (B) F, HCOOH (C) F .CH,OCH, (D) Both (B)

Xelga [282]

Answer:

(B) F⁻, HCOOH

Explanation:

(A) CH₄, HCOOH

(B) F⁻, HCOOH

(C) F⁻, CH₃-O-CH₃

The hydrogen bonds are formed when the hydrogen is found between two electronegative atoms such as oxygen (O), nitrogen (N) or florine (F).

O····H-O, F····H-O, O····H-N

(A) CH₄, HCOOH

- here methane CH₄ is not capable to form hydrogen bond with water

- formic acid HCOOH can form hydrogen bonds with water

H-C(=O)-O-H····OH₂

(B) F⁻, HCOOH

-both floride (F⁻) and formic acid can form hydrogen bonds with water

F····OH₂

H-C(=O)-O-H····OH₂

(C) F⁻, CH₃-O-CH₃

- dimethyl-ether CH₃-O-CH₃ is not capable to form hydrogen bond with water

- floride (F⁻) can form hydrogen bonds with water

F····OH₂

4 0

3 years ago

(Thermodynamics)

frutty [35]

Answer:

3853 g

Step-by-step explanation:

M_r: 107.87

16Ag + S₈ ⟶ 8Ag₂S; ΔH°f = -31.8 kJ·mol⁻¹

1. Calculate the moles of Ag₂S

Moles of Ag₂S = 567.9 kJ × 1 mol Ag₂S/31.8kJ = 17.858 mol Ag₂S

2. Calculate the moles of Ag

Moles of Ag = 17.86 mol Ag₂S × (16 mol Ag/8 mol Ag₂S) = 35.717 mol Ag

3. Calculate the mass of Ag

Mass of g = 35.717 mol Ag × (107.87 g Ag/1 mol Ag) = 3853 g Ag

You must react 3853 g of Ag to produce 567.9 kJ of heat

3 0

3 years ago

Two 10g blocks, one of copper and one of iron, were heated from 300 K to 400K (a temperature difference of 100 K).

12345 [234]

1) 385 J

2) 450 J

Explanation:

1)

The amount of energy that must be absorbed by a certain substance in order to increase its temperature by $\Delta T$ is given by the equation:

$Q=mC\Delta T$

where

m is the mass of the substance

C is its specific heat capacity

$\Delta T$ is the increase in temperature of the substance

For the block of copper in this problem, we have:

m = 10 g is the mass

$C=0.385 J/gK$ is the specific heat capacity of copper

$\Delta T=400-300 = 100 K$ is the change in temperature

So, the energy absorbed by the block of copper is

$Q=(10)(0.385)(100)=385 J$

2)

Similarly for the block of iron, the energy absorbed by the iron is given by

$Q=mC\Delta T$

where

m is the mass of the block of iron

C is its specific heat capacity of iron

$\Delta T$ is the increase in temperature of the block

Here we have:

m = 10 g is the mass of the block

$C=0.450 J/gK$ is the specific heat capacity of iron

$\Delta T=400-300 = 100 K$ is the change in temperature

So, the energy absorbed by the block of iron is

$Q=(10)(0.450)(100)=450 J$

6 0

3 years ago

Which step in naming unsaturated hydrocarbons is used for alkenes but not alkynes?

Slav-nsk [51]

Answer:

Examine the multiple bond for cis- and trans- isomers.

Explanation:

6 0

3 years ago

Read 2 more answers

what is the boiling point of the solution resulted from the dissolving of 32.5g of NaCl in 250.0g of water?

suter [353]

Answer:

The boiling point of this solution is 102.28 °C

Explanation:

Step 1: Data given

Mass of Nacl = 32.5 grams

Molar mass of NaCl = 58.45 g/mol

Mass of Water = 250 grams

Boiling point of water = 100°C

Step 2: Calculate number of moles

Number of moles = mass of NaCl / Molar mass of NaCl

Number of moles = 32.5 grams /58.45 g/mol = 0.556 moles

Step 3: Calculate molality

Molality = Number of moles / mass of water

Molality = 0.556 moles / 0.250 kg of water

Molality = 2.224 molal

NaCl releases twice as many moles of ions, the total molality of this solution is also twice: 4.448 molal

Step 4: Calculate boiling point

dT =( 0.512 C / molal)*4.448 molal)

dT = 2.28

The boiling point of this solution is 100 °C + 2.28 °C = 102.28 °C

8 0

3 years ago