A gas has a volume of 27.5 L at 302 K and 1.40 atm. How many moles are in the sample of gas?

Determine the mass of sodium acetate necessary to produce 100 ml of an acetate buffer

sasho [114]

Explanation:

Ethanoic acid is a weak acid and dissociates:

C

H

3

C

O

H

⇌

C

H

3

C

O

−

+

H

+

For which

K

a

=

[

C

H

3

C

O

−

]

[

H

+

]

[

C

H

3

C

O

H

]

=

1.8

×

10

−

5

Please remember that these are equilibrium concentrations .

p

K

a

=

−

log

K

a

=

−

log

[

1.8

×

10

−

5

]

=

4.74

n

=

c

×

v

∴

n

C

H

3

C

O

H

=

0.20

×

200.0

1000

=

0.04

3 0

3 years ago

Calculate the pH of a 0.2 M * 4 solution for which Kb = 1.8*10^-5 at 26 c . The equation for the reaction

lara31 [8.8K]

<u>Answer:</u> The pH of the solution is 11.24

<u>Explanation:</u>

We are given:

Molarity of ammonia = 0.2 M

$K_b=1.8\times 10^{-5}$

The given chemical equation follows:

$NH_3+H_2O\rightleftharpoons NH_4^++OH^-$

I: 0.2

C: -x +x +x

E: 0.2-x x x

The expression for equilibrium constant follows:

$K_b=\frac{[NH_4^+][OH^-]}{[NH_3]}$

Putting values in above expression, we get:

$1.8\times 10^{-5}=\frac{x^2}{0.2-x}\\\\1.8\times 10^{-5}(0.2-x)=x^2\\\\x^2+(1.8\times 10^{-5}x)-(0.36\times 10^{-5})=0\\\\x=1.88\times 10^{-3}, 1.9\times 10^{-3}$

Neglecting the negative value of x as concentration cannot be negative.

So, $[OH^-]=x=1.88\times 10^{-3}M$

pOH is defined as the negative logarithm of hydroxide ion concentration present in the solution.

$pOH=-\log [OH^-]$

Putting values in above equation, we get:

$pOH=-\log (1.88\times 10^{-3})\\\\pOH=2.76$

We know:

$pH+pOH=14\\\\pH=14-2.76\\\\pH=11.24$

Hence, the pH of the solution is 11.24

6 0

3 years ago

noble gases, such as argon and neon, are known for being extremely non-reactive. neon and argon are non-reactive because they

nadezda [96]

They have a complete electronic configuration .their P shell is p6 therefore cannot gain or loose electron.

4 0

3 years ago

Can someone answer this for me and show proof I WILL MARK BRAINLIEST

AlexFokin [52]

Answer:

A

Explanation:

Caus it makes sense

7 0

3 years ago

If a man has a mass of 83 kilograms on Earth, what will the force of gravity on his body be on the moon?

VladimirAG [237]

The answer is (A.) 135.6 N

————

Here is the formula you will need to answer the question.

Formula:
Force(N) = Mass(kg) x Acceleration(m/s²)
or... F(N) = m(kg) x a(m/s²)

————

We need to be certain of the information presented. The problem says the man has a "Mass" of 83 kilograms on Earth. If a man has a Mass of 83 kilograms on Earth, he has a mass of 83 kilograms everywhere. The mass for this problem (even on the moon) is 83.

Mass(kg): 83

————

To find the acceleration of object on other planets, moons, ect, you'll need to search the internet or ask a teacher. There are ways to calculate this, but the problem didn't supply the necessary information to do so.

Acceleration: 1.625 m/s²

————

Now just plug the information into the formula.

F(N) = m(kg) x a(m/s²)

N = 83 x 1.625
N= 135.875

When considering that there could be a slighty more accurate number for acceleration, it can be concluded that the best answer is (A.)

3 0

4 years ago