All categories

3 years ago

What is the ph of a buffer that consists of 0.45 m ch3cooh and 0.35 m ch3coona? ka = 1.8 × 10–5?

Chemistry

1 answer:

oee [108]3 years ago

8 0

Answer is: pH of a buffer is 4.64.

ck(CH₃COOH) = 0.45 M.

cs(CH₃COONa) = 0.35 M.

Ka = 1.8·10⁻⁵.

pKa = -logKa.
pKa = -log(1.8·10⁻⁵) = 4.75.
Henderson–Hasselbalch equation: pH = pKa + log(cs/ck).
pH = 4.75 + log(0.35M/0.45M).
pH = 4.75 - 0.11.
pH = 4.64.

pH (potential of hydrogen) is a numeric scale used to specify the acidity or basicity an aqueous solution.

You might be interested in

What is amu of 99 % H-1, .2% H-1 and .8% H-3

ankoles [38]

The average atomic mass of your mixture is 1.03 u .

The average atomic mass of H is the weighted average of the atomic masses of its isotopes.

We multiply the atomic mass of each isotope by a number representing its relative importance (i.e., its % abundance).

Thus,

0.99 × 1.01 u = 0.998 u

0.002 × 2.01 u = 0.004 u

0.008 × 3.02 u = 0.024 u

TOTAL = 1.03 u

4 0

3 years ago

A 50.0-g sample of liquid water at 25.0 Â°c is mixed with 23.0 g of water at 79.0 Â°c. the final temperature of the water is ___

I am Lyosha [343]

m1ΔT1+m2ΔT2=0

m1(Tfl–lT∘1)+m2(Tfl–lT∘2)=0

50.0g×(Tfl–l25.0 °C)+23.0g×(Tfl–l57.0 °C)=0

50.0Tf−1250 °C+23.0Tf – 1311 °C=0

73.0Tf=2561 °C

Tf=2561 °C73.0=35.1 °C

8 0

3 years ago

What is the pH of a KOH solution that has [H ] = 1. 87 × 10–13 M? What is the pOH of a KOH solution that has [OH− ] = 5. 81 × 10

vlada-n [284]

pH is the hydrogen ion concentration and pOH is the hydroxide ion concentration in the solution. pH KOH is 12.73, pOH KOH is 2.24 and pH NaCl is 7.

pH is the negative log of the hydrogen ion concentration and pOH is the negative log of the hydroxide ion concentration.

The relation between the pH and pOH can be given as, $\rm pOH = 14 - pH$

The pH of KOH can be calculated by the formula,

$\rm pH = \rm -log [H^{+}]$

In the first case, the concentration of the KOH is $1. 87 \times 10^{-13}\;\rm M$

Substituting values in the equation:

$\begin{aligned} \rm pH &= \rm -log [H^{+}]\\\\&= \rm -log [1. 87 \times 10^{-13}\;\rm M ]\\\\&= 12.73\end{aligned}$

Hence, the pH of KOH is 12.73.

pOH of KOH can be calculated by the formula,

$\rm pOH = \rm -log [OH^{-}]$

The hydroxide concentration of the KOH solution is $5. 81 \times 10^{-3}\;\rm M$

Substituting value in the equation:

$\begin{aligned} \rm pOH &= \rm -log [OH^{-}]\\\\&= \rm -log [5. 81 \times 10^{-3}\;\rm M ]\\\\&= 2.24 \end{aligned}$

Hence, the pOH of KOH is 2.24

The pH of NaCl can be calculated by the formula,

$\rm pH = \rm -log [H^{+}]$

In the third case, the concentration of the NaCl is $1. 00\times 10^{-7}\;\rm M$

Substituting values in the equation:

$\begin{aligned} \rm pH &= \rm -log [H^{+}]\\\\&= \rm -log [1. 00 \times 10^{-7}\;\rm M ]\\\\&= 7 \end{aligned}$

Hence, the pH of KOH is 7.0.

Therefore, KOH is basic and NaCl is approximately neutral.

Learn more about pH and pOH here:

brainly.com/question/13885794

3 0

2 years ago

Why can metals be extracted using carbon

8090 [49]

If a metal is less reactive than carbon, it can be extracted from its oxide by heating with carbon. The carbon displaces the metal from the compound, and removes the oxygen from the oxide. This leaves the metal.

5 0

2 years ago

HELP ASAP***

Alchen [17]

D...........................

8 0

3 years ago

Read 2 more answers