1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
dalvyx [7]
3 years ago
10

n unknown weak acid, HA, it titrated with 0.6 M NaOH. The pH at the halfway point of this titration was found to be 4.215. If th

e initial pH of the weak acid solution (before titration) has a pH of 2.148, what was the concentration of the weak acid solution
Chemistry
1 answer:
Len [333]3 years ago
6 0

Answer:

The concentration of the weak acid was the antilog of the initial pH =  <u>7.112 × </u>10^{-3}<u> M</u>

Explanation:

We are given the initial pH of the weak acid HA to be = 2.148.

Since pH = - log [HA]

⇒ [HA] = 10^{-pH} = 10^{-2.148}

[HA] = 7.112 × 10^{-3} M ≡ 0.0007112 M

You might be interested in
A mixture containing nitrogen and hydrogen weighs 3.48 g and occupies a volume of 7.47 L at 296 K and 1.02 atm. Calculate the ma
Sonbull [250]

Answer:

there is 2% of hydrogen and 98% of nitrogen (mass percent)

Explanation:

assuming ideal gas behaviour

P*V=n*R*T

n= P*V/(R*T)

where P= pressure=1.02 atm , V=volume=7.47 L , T=absolute temperature= 296 K and R= ideal gas constant = 0.082 atm*L/(mole*K)

thus

n= P*V/(R*T) = 1.02 atm*7.47 L/( 296 K * 0.082 atm*L/(mole*K)) = 0.314 moles

since the number of moles is related with the mass m through the molecular weight M

n=m/M

thus denoting 1 as hydrogen and 2 as nitrogen

m₁+m₂ = mt (total mass)

m₁/M₁+m₂/M₂ = n

dividing one equation by the other and denoting mass fraction w₁= m₁/mt , w₂= m₂/mt , w₂= 1- w₁

w₁/M₁+w₂/M₂ = n/mt

w₁/M₁+(1-w₁) /M₂ = n/mt

w₁*(1/M₁- 1/M₂) + 1/M₂ = n/mt

w₁=  (n/mt- 1/M₂) /(1/M₁- 1/M₂)

replacing values

w₁=  (n/mt- 1/M₂) /(1/M₁- 1/M₂) = (0.314 moles/3.48 g - 1/(14 g/mole)) /(1/(1 g/mole)-1/(14 g/mole))= 0.02 (%)

and w₂= 1-w₁= 0.98 (98%)

thus there is 2% of hydrogen and 98% of nitrogen

4 0
3 years ago
2.5 piece of lithium is dropped into a 500 g sample of water at 22.1 C.ten temperature of the water increases to 23.5 C. How muc
Dominik [7]

Answer:

2.6 kJ  

Explanation:

The formula for the amount of heat (q) absorbed by the water is

q = mCΔT

1. Calculate ΔT

ΔT = 23.5 °C - 22.1 °C = 1.4 °C

2. Calculate q

q₂ = mCΔT = 500 g × 4.184 J·°C⁻¹g⁻¹ × 1.4 °C = 2900 J = 2.9 kJ

3 0
4 years ago
Which layer contains almost 90% of the atmosphere's total mass?
Afina-wow [57]
The answer is the troposphere

4 0
3 years ago
How do you find the number of protons for any atom
abruzzese [7]

The number of protons in the nucleus of the atom is equal to the atomic number. So the number of atomic number is equal to the number of protons. hope it helped (:

4 0
3 years ago
Read 2 more answers
The radioactive isotope 210/84 Po decays by alpha emission.
yan [13]

The half-life of polonium-210, given that it decays from 98.3 micrograms to 12.3 micrograms in 414 days is 138 days

<h3>How to determine the number of half-lives </h3>
  • Original amount (N₀) = 98.3 micrograms
  • Amount remaining (N) = 12.3 micrograms
  • Number of half-lives (n) =?

2ⁿ = N₀ / N

2ⁿ = 98.3 / 12.3

2ⁿ = 8

2ⁿ = 2³

n = 3

<h3>How to determine the half life </h3>
  • Number of half-lives (n) = 3
  • Time (t) = 414 days
  • Half-life (t½) = ?

t½ = t / n

t½ = 414 / 3

t½ = 138 days

Learn more about half life:

brainly.com/question/26374513

#SPJ1

4 0
2 years ago
Read 2 more answers
Other questions:
  • Can you guys please help me with the second one?
    11·1 answer
  • Is dry ice subliming, endothermic or exothermic??
    5·1 answer
  • How does the density of a gas affect the speed of sound
    10·1 answer
  • It’s due tomorrow morning plz help :((
    10·1 answer
  • Types OF SALTS<br>two examples​
    8·1 answer
  • Nonmetals such as Cl combine with metals such as Na by what
    14·1 answer
  • Airplane cabins are pressurized so passengers can breathe comfortably at altitudes of up to 9,200 meters (30,000 feet).The air p
    13·2 answers
  • If matter is uniform throughout, cannot be separated into other substances by physical processes, but can be decomposed into oth
    12·1 answer
  • What did you have to look at it in order to correctly measure the amount of water in the graduated cylinder?
    7·2 answers
  • what are some of the main things a girl will do if she likes you (YES THIS IS CHEMISTRY) so I'm not breaking the rules
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!