1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
DaniilM [7]
3 years ago
12

The freezing point of benzene C6H6 is 5.50°C at 1 atmosphere. A nonvolatile, nonelectrolyte that dissolves in benzene is DDT . H

ow many grams of DDT, C14H9Cl5 (354.5 g/mol), must be dissolved in 209.0 grams of benzene to reduce the freezing point by 0.400°C ?
Chemistry
1 answer:
Vlad1618 [11]3 years ago
4 0

Answer: 0.028 grams

Explanation:

Depression in freezing point :

Formula used for lowering in freezing point is,

\Delta T_f=k_f\times m

or,

\Delta T_f=k_f\times \frac{\text{ Mass of solute in g}\times 1000}{\text {Molar mass of solute}\times \text{ Mass of solvent in g}}

where,

\Delta T_f = change in freezing point

k_f = freezing point constant  (for benzene} =5.12^0Ckg/mol

m = molality

Putting in the values we get:

0.400^0C=5.12\times \frac{\text{ Mass of solute in g}\times 1000}{354.5\times 209.0}

{\text{ Mass of solute in g}}=0.028g

0.028 grams of DDT (solute) must be dissolved in 209.0 grams of benzene to reduce the freezing point by 0.400°C.

You might be interested in
What is the Celsius temperature of 1 mole of a gas that has an average kinetic energy of 4,290 joules?
timofeeve [1]
Well the the answer is 70.8c but if you round it up it is 71c which I choice and got it correct so the answer is 71c

5 0
3 years ago
Which of the following pairs of elements belong to the same group
ale4655 [162]
C. C and Pb; Carbon and Lead being in the same group.
5 0
2 years ago
Predict the sign of the entropy change,Delta S, for each of the following reactions:The signs are either going to be pos or nega
algol [13]

Answer: a) Pb^{2+}(aq)+2Cl^-(aq)\rightarrow PbCl_2(s):  negative

b)  CaCO_3(s)\rightarrow CaO(s)+CO_2(g) : positive

c) 2NH_3(g)\rightarrow N_2(g)+3H_2(g): positive.

d) P_4(g)+5O_2(g)\rightarrow P_4O_{10}(s) : negative

e) C_4H_8(g)+6O_2(g)\rightarrow 4CO_2(g)+4H_2O(g):  positive.

f) I_2(s)\rightarrow I_2(g) : positive.

Explanation:

Entropy is the measure of randomness or disorder of a system. If a system moves from  an ordered arrangement to a disordered arrangement, the entropy is said to decrease and vice versa.

\Delta S is positive when randomness increases and \Delta S is negative when randomness decreases.

a) Pb^{2+}(aq)+2Cl^-(aq)\rightarrow PbCl_2(s)

As ions are moving to solid form , randomness decreases and thus sign of \Delta S is negative.

b) CaCO_3(s)\rightarrow CaO(s)+CO_2(g)

As solid is changing to gas, randomness increases and thus sign of \Delta S is positive.

c) 2NH_3(g)\rightarrow N_2(g)+3H_2(g)

As 2 moles of reactants are converted to 4 moles of products , randomness increases and thus sign of \Delta S is positive.

d) P_4(g)+5O_2(g)\rightarrow P_4O_{10}(s)

As gas is changing to solid, randomness decreases and thus sign of \Delta S is negative.

e) C_4H_8(g)+6O_2(g)\rightarrow 4CO_2(g)+4H_2O(g)

As 7 moles of reactants are converted to 8 moles of products , randomness increases and thus sign of \Delta S is positive.

f) I_2(s)\rightarrow I_2(g)

As solid is changing to gas, randomness increases and thus sign of \Delta S is positive.

6 0
3 years ago
NEED HELP FAST
Blababa [14]

Answer: 1. Ethylene is a stable molecule with two carbon atoms connected by a double bond. Polyethylene is made by the reaction of multiple ethylene molecules in the presence of a catalyst.

2. The term “plastics” includes materials composed of various elements such as carbon, hydrogen, oxygen, nitrogen, chlorine, and sulfur.

3. Polyethylene (PE) is made by the reaction of multiple ethylene molecules in the presence of catalysts to break the double bond and connect the carbon atoms into a chain . The longer the chain, the higher the molecular weight. Polymers can have molecular weights in the millions.

Explanation:

6 0
3 years ago
What is the difference between mass number and average atomic mass?
myrzilka [38]

Answer:

the answer is c. I think

Explanation:

4 0
3 years ago
Other questions:
  • A screw has 4 threads per centimeter and a circumference of 2 centimeters. The mechanical advantage of the screw is?
    8·2 answers
  • Green plants absorb sunlight to power photosynthesis, the chemical synthesis of food from water and carbon dioxide. The compound
    6·1 answer
  • Which of the following is a type of kinetic energy.
    12·1 answer
  • Help plz need answers asap
    9·2 answers
  • In IR spectroscopy, we normally talk about "frequencies" when in reality we are referring to wavenumbers. What is the mathematic
    14·1 answer
  • Question 1 of 10
    15·1 answer
  • What is the percent composition by mass of sulfur in the compound MgSO4 (gram-formula mass =120. grams per mole)?(1) 20.% (2) 27
    12·1 answer
  • In an accident, a solution containing 2.5 kg of nitric acid was spilled. Two kilograms of Na2CO3 was quickly spread on the area
    14·1 answer
  • Perform the following operation
    9·1 answer
  • Calcular el numero de gramos de un mol de metano
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!