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
inn [45]
4 years ago
11

What is the pH of a 40.0 40.0 mL solution that is 0.11 0.11 M in CN − CN− and 0.21 0.21 M in HCN HCN ? The K a Ka for HCN is 4.9

× 10 − 9
Chemistry
1 answer:
cluponka [151]4 years ago
6 0

Answer:

pH=8.03

Explanation:

From the Henderson-Hasselbalch equation:

we know that

pH = pKa + log (base / acid)

plugging the values from the question we can write

pH = 8.31 + log (0.11 / 0.21)

pH = 8.31-0.280

pH=8.03

You might be interested in
A 100kg sumo wrestler named Bob is doing his daily run. He runs at a velocity of 8m/s. After the run Bob stops for a rest, and s
Elza [17]

Answer:

0 kgm/s

Explanation:

The momentum of Bob while resting at the river is 0 kgm/s.

This is because the momentum of any object at rest is 0.

 Momentum is the quantity of motion a body contains. It is mathematically expressed as;

  Momentum  = m x v

m is the mass

v is the velocity

 So at rest, the velocity of a body is 0m/s and therefore, the momentum is O

5 0
3 years ago
BRAINLIESTTT ASAP!!!! PLEASE HELP ME :)
Elan Coil [88]

Answer:

1s² 2s²2p³  

Explanation:

If the atom has seven electrons, it is Element 7 (nitrogen).

In the Periodic Table, you count the electrons in all the subshells up to

No. 7.

In the first Period, you have filled the 1s level (2 electrons).

In the second Period, you have filled the 2s subshell (2 electrons) and put three electrons in the 2p subshell.

Thus, the electron configuration is

1s² 2s²2p³

Note how the superscripts tell you the number of electrons in each subshell: <em>2 + 2 + 3 = 7</em>.

6 0
3 years ago
Element X is a radioactive isotope such that every 82 years, its mass decreases by half. Given that the initial mass of a sample
lesantik [10]

Answer: 17 years

Explanation:

Expression for rate law for first order kinetics  for radioactive substance is given by:

t=\frac{2.303}{k}\log\frac{a}{a-x}

where,

k = rate constant

t = age of sample

a = let initial amount of the reactant

a - x = amount left after decay process  

a) for completion of half life:

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

t_{\frac{1}{2}}=\frac{0.693}{k}

k=\frac{0.693}{82years}=8.4\times 10^{-3}years^{-1}

b) for 8900 g of the mass of the sample to reach  7700 grams

t=\frac{2.303}{8.4\times 10^{-3}}\log\frac{8900}{7700}

t=17years

Thus it will take 17 years

4 0
3 years ago
Hi can you help me with these questions please
joja [24]

Answer:

iron oxide11

Explanation:

iron oxide is the chemical compound with formula fe304. it occurs in nature as the mineral magnetite.

6 0
3 years ago
Read 2 more answers
How do I find the volume of a gas at stp if it’s volume is 80.0mL at 109kPa and -12.5 degrees Celsius
Hatshy [7]

all i really know is that STP (standard temperature and pressure) represents conventional conditions established by IUPAC with T = 273.15 K, P = 1 atm . Now putting these values of temperature and pressure at STP, we can calculate easily volume occupied by 1 mol of gas and which comes out to be 22.4 L. hope this helps

4 0
3 years ago
Read 2 more answers
Other questions:
  • In the preparatory reaction which involves moving pyruvic acid into the mitochondrion
    7·1 answer
  • Which law is associated with inertia
    5·1 answer
  • Select the type of energy involved in each step.
    10·2 answers
  • If the atomic radius of aluminum is 0.143 nm, calculate the volume of its unit cell in cubic meters.
    14·1 answer
  • Hydrogen has an average atomic mass of 1.008 amu and has 3 known isotopes
    11·1 answer
  • Fossils allow us to analyze how organisms have changed over time. In which type of fossil does the organism get pressured and he
    7·1 answer
  • If the pKa value for a given acid is low, what does that say about the acid (is it weak or strong)?
    15·1 answer
  • 1 point
    11·1 answer
  • How many moles are in 24.75 g of H2O? What is given the conversation and the unknown?
    10·1 answer
  • Please help me I’m very very lazy-(Science)
    9·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!