Cow’s milk is 4.5% by mass of lactose. Calculate the mass of lactose present in 175 g of milk

Write equations that show the processes that describe the first, second, and third ionization energies for a gaseous iron atom.

Nikolay [14]

The ionization energy of an element is the amount of energy required to remove one mole of electrons from the element in its gaseous state. The equations for the first three are:

Fe(g) → Fe⁺(g) + e⁻

Fe⁺(g) → Fe⁺²(g) + e⁻

Fe⁺²(g) → Fe⁺³(g) + e

7 0

2 years ago

What volume of water should be used to dissolve 19.6 g of LiF to create a 0.320 M solution?

USPshnik [31]

Answer:

2.4 litters of water are required.

Explanation:

Given data:

Mass of LiF = 19.6 g

Molarity of solution = 0.320 M

Volume of water used = ?

Solution:

Number of moles = mass/molar mass

Number of moles = 19.6 g/ 26 g/mol

Number of moles = 0.75 mol

Volume required:

Molarity = number of moles/ volume in L

Now we will put the values in above given formula.

0.320 M = 0.75 mol / volume in L

Volume in L = 0.75 mol /0.320 M

M = mol/L

Volume in L = 2.4 L

4 0

2 years ago

Why does silver iodide have a higher melting point than vanillin

MAVERICK [17]

AgI has a higher melting point than vanillin because it is an ionic compound. The bonds are held more tightly together than in vanillin because it is a covalent compound. Ionic bonds have a higher melting point because the electrons are being transferred from one atom to the other.

5 0

2 years ago

The pKs of succinic acid are 4.21 and 5.64. How many grams of monosodium succinate (FW = 140 g/mol) and disodium succinate (FW =

Varvara68 [4.7K]

Answer:

9.744g of monosodium succinate.

4.925g of disodium succinate.

Explanation:

To find pH of the buffer produced by the mixture of monosodium succinate-Disodium succinate is obtained from H-H equation:

pH = pKa + log ([Na₂Suc] / [NaHSuc])

As you want a pH of 5.28 and pKa is 5.64:

5.28 = 5.64 + log ([Na₂Suc] / [NaHSuc])

-0.36 = log ([Na₂Suc] / [NaHSuc])

0.4365 = ([Na₂Suc] / [NaHSuc]) (1)

As total concentration of the buffer is 100mM = 0.100M:

0.100M = [Na₂Suc] + [NaHSuc] (2)

Replacing (2) in (1):

0.4365 = (0.100M - [NaHSuc] / [NaHSuc])

0.4365 [NaHSuc] = 0.100M - [NaHSuc]

1.4365 [NaHSuc] = 0.100M

[NaHSuc] = 0.0696M

And:

[Na₂Suc] = 0.0304M

As volume of the buffer is 1L:

[NaHSuc] = 0.0696 moles

[Na₂Suc] = 0.0304 moles

Using molar mass of both substances:

Mass of monosodium succinate:

0.0696moles * (140g / 1mol) = 9.744g of monosodium succinate.

Mass of disodium succinate:

0.0304moles * (162g / 1mol) = 4.925g of disodium succinate.

5 0

2 years ago

Many free radicals combine to form molecules that do not contain any unpaired electrons. The driving force for the radical–radic

Alexxandr [17]

Answer:

In the attached image the Lewis equation is shown where it is shown how two oxygens react with two hydrogens to meet the octet of the electrons.

Explanation:

Hydrogen peroxide is one of the most named chemicals since it is not only sold as "hydrogen peroxide" in pharmacies but it is also one of the great weapons of immune defense cells to defend ourselves against anaerobic bacteria.

The disadvantage of this compound is that when dividing it forms free oxygen radicals that are considered toxic or aging for our body.

4 0

2 years ago