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2 years ago

Cells have a _____, a thin layer that controls what goes in and out of the cell.

Chemistry

2 answers:

dezoksy [38]2 years ago

7 0

Pretty sure it’s cell membrane

Iteru [2.4K]2 years ago

3 0

Answer:

cell membrane

Explanation:

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Be sure to answer all parts. What is the effect of each of the following on the volume of 1 mol of an ideal gas? (a) The pressur

aksik [14]

Answer

A)The volume decreases by a factor of 4

B), the volume has increased by factor of 2

Explanation:

A)Given:

P1= 760Kpa

P2 =202Kpa

The temperature changes from37C to155C

There is increase In pressure from P1 to P2

P1= 760torr.

We need to convert to Kpa

But, 1atm= 760torr

Then 760torr 101000pa

Then 101000pa = 101Kpa

We need to convert the temperature from Celsius to Kelvin

T1= 37+273= 310K

But from ideal gas, we know that PV = nRT where nR is constant

Where P= pressure

V= volume

T= temperature

n = number of moles

(P1V1/T1)=(P2V2/T2)

V1/V2 = P2/P1 * T1/T2

V1/V2 = (202/101)*(310/155)

V1/V2=4

$V2= V1/4$

Therefore, the volume has decreased by factor of 4

Given:

P1= 2atm

P2 =101Kpa

The temperature changes from 305K to 32C

There is increase In pressure from P1 to P2

P1= 2atm

We need to convert to Kpa

But, 1atm= 760torr

Then 760torr 101000pa

Then 101000pa = 101Kpa

P1= 202.65kpa

We need to convert the temperature from Celsius to Kelvin

T2= 32+273= 305K

But from ideal gas, we know that PV = nRT

Where P= pressure

V= volume

T= temperature

n = number of moles

(P1V1/T1)=(P2V2/T2)

V1/V2 = P2/P1 * T1/T2

V1/V2 = (202/101)

V1/V2 = (101/202.65)*(305/305)

V1/V2 = 1/2

$V2=2V1$

Therefore, the volume has increased by factor of 2

4 0

2 years ago

Which of the following represents the least number of molecues?

Mars2501 [29]

Answer:

Answer: a) 20g of H2O (18.02 g/mol) molecules=6.68x10^23

Explanation:

In order to find the amount of molecules of each of the options, we need to follow the following equation.

$molecules=\frac{mass(g)x6.022x10^{23}(molecules/mol) }{atomic weight(g/mol)}$

So, let´s get the number of molecules for each of the options.

$a) molecules=\frac{20(g)x6.022x10^{23}(molecules/mol) }{18.02(g/mol)}=6.68x10^{23}molecules$

$b) molecules=\frac{77(g)x6.022x10^{23}(molecules/mol) }{16.06(g/mol)}=2.89x10^{24}molecules$

$c) molecules=\frac{68(g)x6.022x10^{23}(molecules/mol) }{42.09(g/mol)}=9.73x10^{23}molecules$

$d) molecules=\frac{100(g)x6.022x10^{23}(molecules/mol) }{44.02(g/mol)}=1.37x10^{24}molecules$

$d) molecules=\frac{84(g)x6.022x10^{23}(molecules/mol) }{20.01(g/mol)}=2.53x10^{24}molecules$

the smalest number is in option a)

Best of luck.

7 0

2 years ago

While following the Dumas method, a student assumes that the contents of the container are the same temperature as the water bat

Nataliya [291]

Answer:

Explanation:

the Molar mass will be smaller as the content of the container is not directly proportional to the temperature of the water bath.

5 0

3 years ago

What is the approximate geometry around each oxygen atom

AnnyKZ [126]

Answer:

correct option: A. tetrahedral

Explanation:

when we talk about hydrogen bonding in water due to oxygen then need to check the number of lone pair available for hydrogen bonding because hydrogen bond form between lone pair of oxygen and hydrogen of other water molecule so there are two lone pair which forms hydrogen bond and there are also two other covalent bond with hydrogen of same molecule so total number is 4 it means they will form a tetrahedral geometry

7 0

3 years ago

If the volume and Kelvin temperature are reduced by one-half what will happen to the pressure???

jolli1 [7]

Answer:

the pressure will decrease

Explanation:

6 0

3 years ago

Cells have a ______ ___________, a thin layer that controls what goes in and out of the cell.

Cells have a _____, a thin layer that controls what goes in and out of the cell.