Ask question

Ask question

All categories

3 years ago

14

A phosphate buffer is prepared with KH2PO4 at 0.02 M and K2HPO4 at 0.03 M. What is the concentration of phosphate buffer

1 answer:

Alona [7]3 years ago

6 0

Answer:

0.05M is the concentration of the phosphate buffer

Explanation:

A buffer is defined as the aqueous mixture of a weak acid (KH₂PO₄) and its conjugate base (K₂HPO₄). The concentration of this buffer is the sum of the concentrations of the weak acid and the conjugate base, that is:

Concentration of phosphate buffer = 0.02M + 0.03M

=

<h3>0.05M is the concentration of the phosphate buffer</h3>

<em />

You might be interested in

Which type of model is a way of imagining how something works?

RUDIKE [14]

Answer:

mental model is an explanation of someone's thought process about how something works in the real world. It is a representation of the surrounding world, the relationships between its various parts and a person's intuitive perception about his or her own acts and their consequences. Mental models can help shape behaviour and set an approach to solving problems (similar to a personal algorithm) and doing tasks.

:)

6 0

3 years ago

Read 2 more answers

A solution containing 0.102 g of an unknown compound dissolved in 100. mL of water has an osmotic pressure of 28.1 mmHg at 20.°C

IrinaVladis [17]

Answer:

MM = 680g / mol

Explanation:

Hello! To calculate the molar mass of the compound (g / mol), I first have to calculate the molarity.

Molarity can be calculated from the osmotic pressure equation.

op = M * R * T

op = osmotic pressure = 28.1mmHg * (1 atm / 760mmHg) = 0.037atm

M = molarity

R = gas constant

T = temperature (K) = 20 ° C + 273.15 = 293.15K

M (mol / L) = op / R * T

M = 0.037atm / ((0.082 (atm * L) / (K * mol)) * 293.15K) = 0.0015mol / L

As I have the volume = 100ml * (1L / 1000ml) = 0.1L

I can calculate the amount of moles

n = M * V = 0.0015 * 0.1 = 0.00015mol

n = m / MM

m = mass

MM = molar mass

MM = m / n = 0.102g / 0.00015mol

MM = 680g / mol

4 0

2 years ago

Read 2 more answers

The reaction 2NO(g)+Cl2(g)→2NOCl(g) is carried out in a closed vessel. If the partial pressure of NO is decreasing at the rate o

Luba_88 [7]

Answer : The rate of change of the total pressure of the vessel is, 10.5 torr/min.

Explanation : Given,

$\frac{d[NO]}{dt}$ =21 torr/min

The balanced chemical reaction is,

$2NO(g)+Cl_2(g)\rightarrow 2NOCl(g)$

The rate of disappearance of $NO$ = $-\frac{1}{2}\frac{d[NO]}{dt}$

The rate of disappearance of $Cl_2$ = $-\frac{d[Cl_2]}{dt}$

The rate of formation of $NOCl$ = $\frac{1}{2}\frac{d[NOCl]}{dt}$

As we know that,

$\frac{d[NO]}{dt}$ =21 torr/min

So,

$-\frac{d[Cl_2]}{dt}=-\frac{1}{2}\frac{d[NO]}{dt}$

$\frac{d[Cl_2]}{dt}=\frac{1}{2}\times 21torr/min=10.5torr/min$

And,

$\frac{1}{2}\frac{d[NOCl]}{dt}=\frac{1}{2}\frac{d[NO]}$

$\frac{d[NOCl]}{dt}=\frac{d[NO]}=21torr/min$

Now we have to calculate the rate change.

Rate change = Reactant rate - Product rate

Rate change = (21 + 10.5) - 21 = 10.5 torr/min

Therefore, the rate of change of the total pressure of the vessel is, 10.5 torr/min.

8 0

3 years ago

A 32.8 g iron rod, initially at 22.4 C, is submerged into an unknown mass of water at 63.1 C, in an insulated container. The fin

laila [671]

Answer:

mass water = 32.4 g

Explanation:

specific heat iron = 0.450 J/g°C

specific heat water = 4.18 J/g°C

32.8 x 0.450 ( 59.1 - 22.4) + mass water x 4.18 ( 59.1- 63.1)=0

541.7 - mass water x 16.7 = 0

mass water = 32.4 g

3 0

2 years ago

What information does an equilibrium constant give about a reaction?

Maksim231197 [3]

Answer:

B. It tells whether products or reactants are favored at equilibrium.

6 0

2 years ago