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
Schach [20]
3 years ago
12

URGENT ! PLEASE ANSWER QUICKLY

Chemistry
2 answers:
Bumek [7]3 years ago
7 0

Answer:If we dissolve NaF in water, we get the following equilibrium:

text{F}^-(aq)+text{H}_2text{O}(l) rightleftarrows text{HF}(aq)+text{OH}^-(aq)

The pH of the resulting solution can be determined if the  K_b of the fluoride ion is known.

20.0 g of sodium fluoride is dissolve in enough water to make 500.0 mL of solution. Calculate the pH of the solution. The  K_b of the fluoride ion is 1.4 × 10 −11 .

Step 1: List the known values and plan the problem.

Known

mass NaF = 20.0 g

molar mass NaF = 41.99 g/mol

volume solution = 0.500 L

K_b of F – = 1.4 × 10 −11

Unknown

pH of solution = ?

The molarity of the F − solution can be calculated from the mass, molar mass, and solution volume. Since NaF completely dissociates, the molarity of the NaF is equal to the molarity of the F − ion. An ICE Table (below) can be used to calculate the concentration of OH − produced and then the pH of the solution.

Explanation:

marysya [2.9K]3 years ago
4 0

Answer:

not sure if this is 100% correct but this is what i got first question: molarity=mol/L 5g*1mol/58.44g=5/58.44 =0.085558mol 4.8m=0.085558/L L=0.0178

jiujuan avatar

second question: pH = - log [H3O+] pH= -log [4.6*10^-9] = 8.33724216

Explanation:

You might be interested in
Use the drop-down menus to complete each sentence.
Ipatiy [6.2K]

Explanation:

Elements that belong to same group contains same number of valence electrons. Hence, they tend to show similar chemical properties.

When we move across a period then number of electrons get added to the same shell. As a result, there will be no increase in size of elements.

Also, metals are the elements that belong to group 1, 2 and d-block elements are also known as metals. Metallic character of elements decreases when we move left to right in a periodic table.

As most reactive metals are placed on the left side of periodic table.

Since, size of elements increases on moving down the group. So, an element is able to easily lose its valence electrons because of less force of attraction between its nucleus and valence electrons.

As a result, there will be increase in reactivity of metals on moving down the group.

Thus, we can conclude that given sentences are as follows.

  • Elements in the same group have the same number of valence electrons.
  • Elements in the same period have the same number of electron shells.
  • Metallic elements become less reactive as you move left to right in a period.
  • Metallic elements become more reactive as you move top to bottom in a group.
3 0
3 years ago
Read 2 more answers
PLEASE HELP!
Eduardwww [97]

Answer:

The answer is C, number 4 shows a rift valley

Explanation: This is because the shape of the feature is literally a rift and it forms a valley lol. Also i have some evidence:

7 0
3 years ago
Read 2 more answers
Unscramble the word nlpituloo
nadezda [96]
Hello

The word is "pollution"

Hope this helps and have a great day!
3 0
3 years ago
Read 2 more answers
As a scuba diver descends under water, the pressure increases. At a total air pressure of 2.71 atm and a temperature of 25.0 C,
Semenov [28]

Answer:

1.32\times 10^{-3} mol/Lis the solubility of nitrogen gas in a diver's blood.

Explanation:

Henry's law states that the amount of gas dissolved or molar solubility of gas is directly proportional to the partial pressure of the liquid.

To calculate the molar solubility, we use the equation given by Henry's law, which is:

C_{N_2}=K_H\times p_{liquid}

where,

K_H = Henry's constant = 6.26 \times 10^{-4}mol/L.atm

p_{N_2} = partial pressure of nitrogen

p_{N_2}= P\times \chi_{N_2} (Raoult's law)

=2.71 atm\times 0.78=2.1138 atm

C_{N_2}=6.26 \times 10^{-4}mol/L.atm\times 2.1138 atm

C_{N_2}=1.32\times 10^{-3} mol/L

1.32\times 10^{-3} mol/Lis the solubility of nitrogen gas in a diver's blood.

3 0
3 years ago
What is the mass of 1.6 mol of aluminum atom?
PIT_PIT [208]
Answer = 43.2

Because to find the mass you multiply the amount of moles ( 1.6) by the mass of the element ( mass of aluminium is 27) so
1.6 x 27 = 43.2g

Hope this helps
8 0
3 years ago
Other questions:
  • An acid's hydronium ion will donate its proton to a base's hydroxide ion, _________ both. a. acidifying b. alkalizing c. neutral
    10·1 answer
  • in Analytical chemistry laboratory. Nickle(ppm)in water sample estimated by two different students was as ,student 1 (25 24 24 2
    7·1 answer
  • Which statement a-d about a state function is not correct?
    10·1 answer
  • Given a fixed amount of gas in a rigid container (no change in volume), what pressure will the gas exert if the pressure is init
    12·1 answer
  • Place these in order from smallest to largest.
    5·1 answer
  • What is the total number of moles of sulfur atoms in 1 mole of Fe2(SO4)3
    10·2 answers
  • What is formed when oxygen and hydrogen unite chemically
    8·1 answer
  • Why does a metal bond with a non-metal in ionic bondings?? ASAP please
    12·1 answer
  • Calculate the specific heat in calories per °C of a 2.00 lb pure iron bar.<br> Plz help me!!!
    6·1 answer
  • An unknown compound contains only carbon, hydrogen, nitrogen, and oxygen. Complete combustion of a 2.77 g sample of the compound
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!