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3 years ago

Plz HELP ITS SCIENCE!

Chemistry

2 answers:

Levart [38]3 years ago

7 0

Cell Wall
1) Acts like skin.
2) Rigid.
3)Gives the plant cell its shape.

Cell Membrane
1) is not rigid.
2) More selectively controls what goes in and out of the cell.

Alexxx [7]3 years ago

6 0

Cell wall:
-acts like a skin
- most selectively controls what is inside and outside of the cell
-rigid

Cell membrane:
-gives a plant cell
-not rigid

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Which subatomic particle has negligible mass and travels around outside the nucleus?

allsm [11]

The electron is a subatomic particle that has a negative charge and a negligible mass. The electron travels around out side the nucleus.

The subatomic particles that are inside the nucleus are protons and neutrons.

The answer to your question is electron.

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4 years ago

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Equivalent massof sodium

andre [41]

Answer:

Sodium

Formula : Na

Equivalent mass:23.0

Mark me as Branliest

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3 years ago

Two flasks are connected by a closed valve. One contains gas particles and the other contains a vacuum. If the valve is opened s

Hatshy [7]

Answer: The process by which the particles can reconvene entirely in one of the flasks is: NONSPONTANEOUS.

Explanation:

The spontaneity of a process can affect the distribution of energy and matter within the system. Different chemical or physical processes have the natural tendency to occur in one direction under a given set of conditions. For example:

--> when water is pour down a hill it naturally flows down but it requires outside energy maybe from a water pump to flow up the hill and ,

--> during an iron rust, iron that is exposed to atmosphere will corrode, but rust is not converted to iron without intentional chemical treatment.

Therefore, a spontaneous process is one that occurs naturally under certain conditions. While a NONSPONTANEOUS process, on the other hand, will not take place unless it is initiated by the continual input of energy from an outside source. A process that is spontaneous in one direction under a particular set of conditions is nonspontaneous in the REVERSE direction.

From the two flasks that where connected through a valve, once the valve was opened, the gas spontaneously becomes evenly distributed between the flasks. To reverse this, it would require an external energy making the reconvening of the particles back to the first flask a NONSPONTANEOUS PROCESS .

3 0

3 years ago

BRAINLIEST

NikAS [45]

Answer:

The correct answer is 6.31 M

Explanation:

The molecular weight (MM) of NaOH is calculated as follows:

MM(NaOH) = Molar mass Na + Molar mass O + Molar mass H

= 23 g/mol + 16 g/mol + 1 g/mol

= 40 g/mol

We need the MM to convert from grams to moles. The molarity (moles of solute per liter of solution, in mol/L) can be calculated by dividing the mass into the volume in liters (195 ml = 0.195 L) and then multiplying by the MM as follows:

M = 49.24 g/0.195 L x 1 mol/40 g = 6.31 mol/L = 6.31 M

5 0

4 years ago

Read 2 more answers

4. a) The enthalpy change of combustion of hexane was measured using a calorimeter containing 200 cm3 of water; 0.5g of hexane (

mamaluj [8]

Answer:

The heat of combustion of hexane is -4324kjmol-1

Explanation:

Heat of combustion is the heat evolved when a mole of a substance is burned completely in oxygen under standard conditions.

To solve this problem, all the required values have been given.

Change in temperature ΔT = 30K

Mass of water =200cm3= 200g

Mass of Hexane burned = 0.5g

Step 1:

Find the amount of hear given off

Heat evolved= mass * specific eat capacity of water* temperature change

= 200 * 4.18 * 30

= 25080J

Step 2:

Calculate the relative molecular mass of hexane

RMM of C6H14 = 86g/mole.

Step 3:

Calculate the number of moles of Hexane burned

Numbrt of mole of hexane = mass / molar mass

n = 0.5 / 86

n = 0.0058mole

Step 4:

Calculate the enthalpy change of combustion for 1mole

Combustion of 0.0058mole hexane produces 25080J of heat energy

I mole hexane produces 25080 /0.0058

= 4324kJ of heat energy.

The enthalpy change of combustion of Hexane is -4,324kJmol-1.

There is no need to do anything else for the question.

7 0

3 years ago