Please help!

The ka for hcn is 4.9 ⋅ 10-10. What is the value of kb for cn-?

marusya05 [52]

Answer:

kb = 2,0x10⁻⁵

Explanation:

The ka for HCN is:

HCN ⇄ H⁺ + CN⁻; ka = 4,9x10⁻¹⁰ (1)

The inverse reaction has an equilibrium constant of:

H⁺ + CN⁻ ⇄ HCN k = 1/4,9x10⁻¹⁰ = 2,0x10⁹ (2)

As the equilibrium of the water is:

H₂O ⇄ H⁺ + OH⁻; kw = 1x10⁻¹⁴ (3)

The sum of (2) + (3) gives:

H₂O + CN⁻ ⇄ HCN + OH⁻; kb = kw×k = 1x10⁻¹⁴×2,0x10⁹ =

2,0x10⁻⁶; kb = 2,0x10⁻⁵

-In fact, the general formula to convert from ka to kb is:

kb = kw / ka-

I hope it helps!

5 0

3 years ago

53. Which of the following is NOT a correct interpretation of CH2O, the formula of the compound formaldehyde?

Free_Kalibri [48]

Answer:

B There are two grams of hydrogen for each gram of carbon in this compound.

Explanation:

The second option is a wrong interpretation of this chemical representation of formaldehyde.

Formaldehyde is an organic compound with the formula CH₂O.

As this is the simplest formula of the compound, it is the empirical formula. Also, the formula is the actual one for the compound and it is the molecular formula.

Chemically, the formula shows 1 mole of carbon, 2 moles of H and 1 mole of oxygen in the compound.

A mole of a substance is more a less a unit of measurement in chemistry and it is the amount of substance that contains the avogadro's number of particles.

This ratio is not the mass of chemical species in the compound. You cannot tell the mass of elements in a compound by merely looking at the formula.

7 0

3 years ago

The bond that join the 3'-hydroxyl group of the deoxypentose of one nucleotide to the 5'-hydroxyl group of the deoxypentose of a

lara [203]

Answer:

phosphodiester bond

Explanation:

Phosphodiester linkage/bond is found in deoxyribonucleic and ribonucleic acids. It is formed from a reaction involving the elimination of water from a reaction involving the hydroxyl groups of two different 5-carbon (pentose) sugars and a phosphate group.

The elimination of water, also known as condensation reaction occur twice, resulting in the formation of two ester bonds which then bind the phosphate group to the pentose sugars to become a phosphodiester bond.

The bond links the 3'-hydroxyl group of one of the pentose sugars and the 5'-hydroxyl group of the other pentose sugar in the nucleotides that make up nucleic acids.

8 0

3 years ago

At least three things in your life you think involve chemistry (not from the lesson) and why you think they involve chemistry

timurjin [86]

Food , mixing substances and medicine

7 0

3 years ago

Label each of the following measurements by the quantity each represents. For instance, a measurement of 10.6kg/m3 represents de

postnew [5]

The quantities represented by each of the measurements are

5.0g/mL - Density

37s - Time

47J - Energy or Work

39.56g - Mass

25.3 cm3 - Volume

325 m/s - Time

500m2 - Area

30.23 mL - Volume

2.7 mg - Mass

0.005L - Volume

To determine the quantity each of the measurements represents, we will observe the units.

5.0g/mL

This represents density. Density is the ratio of mass to volume, and mass is measured in grams (g) while volume is measured in milliliters (mL)

37s

This represents time because time is measured in seconds (s)

47J

This represents Energy or Work because they are measured in Joules (J)

39.56g

This represents mass because mass in measured in grams (g)

25.3 cm3

This represents volume because volume is measured in cubic meters (cm³)

325 m s

This represents time. Time can be measured in milliseconds (ms)

500m2

This represents area because area is measured in square meters (m²)

30.23 mL

This represents volume because volume is measured in milliliters (mL)

2.7 mg

This represents mass because mass could be measured in milligrams (mg)

0.005L

This represents volume because volume is measured in liters (L)

Hence, the quantities represented by each of the measurements are

5.0g/mL - Density

37s - Time

47J - Energy or Work

39.56g - Mass

25.3 cm3 - Volume

325 m s - Time

500m2 - Area

30.23 mL - Volume

2.7 mg - Mass

0.005L - Volume

Learn more here: brainly.com/question/1603371

3 0

2 years ago