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4 years ago

Why would the cell membrane shrink when the cells were placed in the 4% salt solution?

1 answer:

8 0

In a salt solution, the water potential is lower than that in the cell. In this case, water molecules will flow from a region of higher water potential to a region of lower water potential by osmosis. Which where water molecules is now flowing out of the cell to the salt solution. Because the cell lose so much water that it now shrinks.
Osmosis is where water molecules move down the water potential gradient through a semi permeable membrane, which is the cell membrane in this case.

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What would the temperature of 0.734 moles of chlorine gas be at 1.83 atmospheres in a 10.2

lesya [120]

Answer: 310K

Explanation:

Given that:

Volume of Chlorine gas V = 10.2L

Temperature T = ?

Pressure P = 1.83 atm

Number of moles of chlorine gas N = 0.734 moles

Molar gas constant R is a constant with a value of 0.0821 atm L K-1 mol-1

Then, apply ideal gas equation

pV = nRT

1.83atm x 10.2L= 0.734 moles x 0.0821 atm L K-1 mol-1 x T

18.67atm L = 0.0603 atm L K-1 x T

T = (18.67atm L / 0.0603 atm L K-1)

T = 309.8K (Round up to 310K)

Thus, the temperature of the chlorine gas is 310 kelvin

5 0

4 years ago

Calculate the amount of heat released in the combustion of 10.5 grams of Al with 3 grams of O2 to form Al2O3(s) at 25°C and 1 at

ElenaW [278]

Answer : The amount of heat released in the combustion is, 209.5 kJ

Explanation :

First we have to calculate the moles of Al and $O_2$ .

$\text{ Moles of }Al=\frac{\text{ Mass of }Al}{\text{ Molar mass of }Al}=\frac{10.5g}{27g/mole}=0.389moles$

$\text{ Moles of }O_2=\frac{\text{ Mass of }O_2}{\text{ Molar mass of }O_2}=\frac{3g}{32g/mole}=0.188moles$

Now we have to calculate the limiting and excess reagent.

The balanced chemical reaction will be:

$4Al+3O_2\rightarrow 2Al_2O_3$

From the balanced reaction we conclude that

As, 3 mole of $O_2$ react with 4 mole of $Al$

So, 0.188 moles of $O_2$ react with $\frac{4}{3}\times 0.188=0.251$ moles of $Al$

From this we conclude that, $Al$ is an excess reagent because the given moles are greater than the required moles and $O_2$ is a limiting reagent and it limits the formation of product.

Now we have to calculate the moles of $Al_2O_3$

From the reaction, we conclude that

As, 3 mole of $O_2$ react to give 2 mole of $Al_2O_3$

So, 0.188 moles of $O_2$ react to give $\frac{2}{3}\times 0.188=0.125$ moles of $Al_2O_3$

Now we have to calculate the amount of heat released in the combustion.

As, 1 mole of $Al_2O_3$ releases amount of heat = 1676 kJ

So, 0.125 mole of $Al_2O_3$ releases amount of heat = $0.125\times 1676kJ=209.5kJ$

Thus, the amount of heat released in the combustion is, 209.5 kJ

4 0

3 years ago

Draw the products of benzoic acid reacting with sodium hydroxide.

Katena32 [7]

Answer:

Products: C6H5COO-Na+ (aq) + H2O (l)

Explanation:

when the benzoic acid react with sodium hydroxide, the acid part i.e carboxyl group is react with the base and produce ionic compound sodium benzoate (C6H5COO-Na+).

Chemical equation:

C6H5COOH + NaOH → C6H5COO-Na+ + H2O

Chemical reaction with physical states:

C6H5COOH (s) + NaOH (aq) → C6H5COO-Na+ (aq) + H2O (l)

Sodium benzoate is very polar ionic compound and soluble in water. If we add HCl into this solution sodium benzoate will be converted back into benzoic acid.

Properties of benzoic acid:

1. it is colorless solid.

2. it is crystalline in nature.

3. it is aromatic compound with the formula C7H6O2.

4. it is soluble into benzene, alcohol and ether.

5. its molar mass is 122.12 g/mol.

Properties of sodium benzoate:

1. Sodium benzoate is white odorless chemical compound.

2. It is aromatic compound and molecular formula is C7H5NaO2.

3. Its molecular weight is 144.11 g/mol.

4. it is sweet in taste and soluble in water.

5. it is used as preservative because of its antimicrobial properties.

Properties of Sodium hydroxide:

1. it is colorless solid and inorganic compound.

2. it is crystalline in nature.

3. its molar mass is 40 g/mol.

4. its molecular formula is NaOH.

5. its melting point is 318 °C.

6 0

3 years ago

1 .

Alenkasestr [34]

Answer : As I understand this is question of matching the correct pairs.
So here are the correct pairs.

1) The attraction between molecules at the surface of a liquid column

---->Surface tension

Surface tension is a phenomenon observed at the <span>surface film of a liquid which is usually caused by the attraction of the particles on the surface layer by the bulk moiety of the liquid, and which tends to minimize its surface area.</span>

2) The energy of motion

----> Kinetic energy

Kinetic energy is the energy which is possessed by an object due to motion.

3) The movement of liquids through the spaces of materials

----> Capillary action

Capillary action is defined as<span> the ability of any liquid to flow through the narrow spaces without any of the assistance, or even in opposition to, external force like gravitational force.</span>

4) The overall movement of suspended or dissolved particles resulting from the random movements of individual particles

----> Diffusion

Diffusion in liquids can be defined as the random movement of particles which are dissolved or are in suspended state in liquid.

5) Attraction of one particle in a material for another

----> Cohesion

Cohesion is defined as the attraction between two different particles in a state of matter

6) The attraction between unlike substances

----> Adhesion

Adhesion is a property of attraction between two unlike substances.

7) A measure oof the resistance of a liquid to flow

----> Viscosity

Viscosity is the term used to define as the resistivity of liquid to flow.

3 0

3 years ago

Read 2 more answers

What do LEGOs and DNA have in common?

dexar [7]

Answer:

They are both building blocks

Explanation:

DNA builds up life while legos build things

4 0

3 years ago