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
Otrada [13]
3 years ago
5

Absalon adds 1 g of salt to 1 L of room temperature water (25 °C). Then, he starts a timer and observes what happens. He notices

that it takes 1 minute for the salt to dissolve. He decides to repeat his experiment, and he adds 1 g of salt to another 1 L of room temperature water (25 °C). After he adds the salt, he starts a timer. But, instead of watching the salt dissolve, he stirs the salt and water with a spoon until it dissolves. He notices that it only takes 30 seconds for the salt to dissolve in his second experiment.
Why does the salt dissolve faster in Absalon's second experiment?


Stirring the salt and water increases the polarity of the water molecules, which causes the ionic bonds of the salt to break.

Stirring the salt and water increases particle motion, which causes more collisions to occur between the water and salt.

Stirring the salt and water increases the surface area of the water, which causes more collisions to occur between the water and salt.

Stirring the salt and water increases the pressure on the solution, which causes the ionic bonds of the salt to break.
Chemistry
2 answers:
igor_vitrenko [27]3 years ago
7 0

Answer: Option (b) is the correct answer.

Explanation:

When Absalon stirred the solution which is containing salt in water then there will occur disturbance into solution due to stirring.

As a result, particles will come in motion and hence, they tend to gain more kinetic energy. Due to which there will be more number of collisions between the solute (salt) and solvent (water) particles.

Hence, rate of reaction will increase and because of this salt will readily dissolve into water.

Thus, we can conclude that the salt dissolve faster in Absalon's second experiment because stirring the salt and water increases particle motion, which causes more collisions to occur between the water and salt.

lana [24]3 years ago
6 0

Answer:

B

Explanation:

I looked it up and found the answer lol

You might be interested in
7.00 of Compound x with molecular formula C3H4 are burned in a constant-pressure calorimeter containing 35.00kg of water at 25c.
beks73 [17]

Answer:

\Delta H_{f,C_3H_4}=276.8kJ/mol

Explanation:

Hello!

In this case, since the equation we use to model the heat exchange into the calorimeter and compute the heat of reaction is:

\Delta H_{rxn} =- m_wC_w\Delta T

We plug in the mass of water, temperature change and specific heat to obtain:

\Delta H_{rxn} =- (35000g)(4.184\frac{J}{g\°C} )(2.316\°C)\\\\\Delta H_{rxn}=-339.16kJ

Now, this enthalpy of reaction corresponds to the combustion of propyne:

C_3H_4+4O_2\rightarrow 3CO_2+2H_2O

Whose enthalpy change involves the enthalpies of formation of propyne, carbon dioxide and water, considering that of propyne is the target:

\Delta H_{rxn}=3\Delta H_{f,CO_2}+2\Delta H_{f,H_2O}-\Delta H_{f,C_3H_4}

However, the enthalpy of reaction should be expressed in kJ per moles of C3H4, so we divide by the appropriate moles in 7.00 g of this compound:

\Delta H_{rxn} =-339.16kJ*\frac{1}{7.00g}*\frac{40.06g}{1mol}=-1940.9kJ/mol

Now, we solve for the enthalpy of formation of C3H4 as shown below:

\Delta H_{f,C_3H_4}=3\Delta H_{f,CO_2}+2\Delta H_{f,H_2O}-\Delta H_{rxn}

So we plug in to obtain (enthalpies of formation of CO2 and H2O are found on NIST data base):

\Delta H_{f,C_3H_4}=3(-393.5kJ/mol)+2(-241.8kJ/mol)-(-1940.9kJ/mol)\\\\\Delta H_{f,C_3H_4}=276.8kJ/mol

Best regards!

7 0
3 years ago
An ideal gas sealed in a rigid 4.86-L cylinder, initially at pressure Pi=10.90 atm, is cooled until the pressure in the cylinder
seraphim [82]

Answer:

\Delta H=-11897J

Explanation:

Hello,

In this case, it is widely known that for isochoric processes, the change in the enthalpy is computed by:

\Delta H=\Delta U+V\Delta P

Whereas the change in the internal energy is computed by:

\Delta U=nCv\Delta T

So we compute the initial and final temperatures for one mole of the ideal gas:

T_1= \frac{P_1V}{nR}=\frac{10.90atm*4.86L}{0.082*n}=\frac{646.02K  }{n} \\\\T_2= \frac{P_2V}{nR}=\frac{1.24atm*4.86L}{0.082*n}=\frac{73.49K  }{n}

Next, the change in the internal energy, since the volume-constant specific heat could be assumed as ³/₂R:

\Delta U=1mol*\frac{3}{2} (8.314\frac{J}{mol*K} )*(73.49K-646.02K )=-7140J

Then, the volume-pressure product in Joules:

V\Delta P=4.86L*\frac{1m^3}{1000L} *(1.24atm-10.90atm)*\frac{101325Pa}{1atm} \\\\V\Delta P=-4756.96J

Finally, the change in the enthalpy for the process:

\Delta H=-7140J-4757J\\\\\Delta H=-11897J

Best regards.

7 0
3 years ago
A compound with molecular formula C5H10O2 has the following 1H NMR spectrum: 1.15 (t, 3H), 1.25 (t, 3H), 2.33 (q, 2H), 4.13 (q,
Vilka [71]

Answer:

Ethyl propionate

Explanation:

Calculating the double bond equivalence as:

DBE =  C - (H/2) - (X/2) + (N/2) +1

Where  

C is the number of carbon atoms

N is the number of nitrogen atoms

X is the number of halogens

H is the number of hydrogen atoms

So, according to the formula, C_5H_{10}O_2

DBE =  5 - (10/2) - (0/2) + (0/2) +1 = 1

It means there is one double bond or one ring.

from the NMR signal, it is clear that compound has two triplet and two quardrate group that means two -CH3 and two -CH2 groups are present.

From the splitting information, it is clear that each the -CH2- group is next to a -CH3, and vice-versa. In this case ring structure is not possible.

The chemical shift of two protons 4.13 ppm(q, 2H) is for protons next to an O atom, therefore, compound must have

-OCH_2CH_3.

Then the signal at 2.33 is for a -CH2-group next to a C=O. So compound must have a structure CH3-CH2-C=O. Now, there is only one way to complete the structure - by bonding the O to the C=O carbon.

So the compound is ethyl propionate

3 0
3 years ago
The ability to perceive others' emotions can be attributed to which of the following parts of the brain?
Marina86 [1]
It is a                                                                                                                                               .......................................................................                                   
5 0
3 years ago
What is one characteristic of a rain forest?
Svetradugi [14.3K]
Different layers makes the most sense due to the fact it can’t be a dry climate because of the vegetation, also there is a lot of plants so minimal plants isn’t an option, and the temperature in a rain forest is usually very humid so cold temperatures can’t be an answer.
7 0
3 years ago
Other questions:
  • Given the equation representing a reaction at equilibrium: N₂ + 3H₂ ⇄ 2NH₃ What occurs when the concentration of H₂ is increased
    8·1 answer
  • 6. How do you identify which is the solute and which is the solvent in solutions that are in the same phase?
    5·1 answer
  • indicators are chemicals that change colour in presence of an acid or an alkali. Universal indicators and pH meters are used to
    10·1 answer
  • Initially, [NH3(g)] = [O2(g)] = 3.60 M; at equilibrium [N2O4(g)] = 0.60 M. Calculate the equilibrium concentration for NH3.
    6·1 answer
  • What is the balanced equation for H3PO4=H4P2O7+H2O
    9·1 answer
  • What are the spectator ions in this reaction
    14·1 answer
  • I’ll give the Brainliest
    8·2 answers
  • Empirical formula for compound of 2.17 mol N and 4.35 mol O
    14·1 answer
  • (1) Some years ago, a crucial experimental error was made during the work-up of the reaction. Instead of adding the reaction mix
    7·1 answer
  • What is a displacement reactions​
    7·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!