All categories

1 year ago

How many moles are in 8.30x10^23 molecules of H2o

Chemistry

2 answers:

sasho [114]1 year ago

8 0

Answer: 1.38 moles

Explanation: According to Avogadro's law, 1 mole of every substance contains Avogadro number of particles (atoms, molecules or ions) i.e. $6.023\times 10^{23}$ particles.

Given : 1 mole molecule of water contains $6.023\times 10^{23}$ molecules of water.

$6.023\times 10^{23}$ molecules are present in = 1 mole

$8.30\times 10^{23}$ molecules will be present in = $\frac{1}{6.023\times 10^{23}}\times 8.30\times 10^{23}=1.38 moles$

Thus $8.30\times 10^{23}$ molecules is equal to 1.38 moles.

LUCKY_DIMON [66]1 year ago

4 0

You multiply avogadro's number to what you were given.
8.30x10^23 * 6. 0221409x10^23
=1.357*10^25

That should be the right answer but I'm not sure. It has been awhile since I have done this.

You might be interested in

Place each charge form of alanine under the pH condition where it would be the predominant form. The pKa values for the carboxyl

damaskus [11]

Answer:

(A) pH < 1 the predominant form is the cation: H3C-C(H)(NH3+)-COOH

(B) pH = pl the predominant form is the zwitterion H3C-C(H)(NH3+)-COO-

(D) Does not occurs in any significant pH: H3C-C(H)(NH2)-COOH

Explanation:

Amino acids are bifunctional because they have an amine group and a carboxyl group. The amine group is a weak base and the carboxyl group is a weak acid, but the pKa of both groups will depend on the whole structure of the amino acid. Also, every amino acid has an isoelectric point (pI), which means the pH were the predominant form of the amino acid is the zwitterion. The structure of the alanine (CH3CH2NH2COOH) shows it has the carboxyl group at C1 with a pKa1 of 2.3 and the amino group at C2 whit the pKa2 of 9.7. The isoelectric poin (pI) of Alanine is 6. Consequently, the protonation of the molecule will depend on the pH of the solution. There are three possibilities:

1) If the pH is under the pKa of the carboxyl group (2.3) the predominant form will be with the amino group protonated, forming a cation (CH3CH(NH3+)COOH).

2) If the pH is between pKa1 (2.3) and pKa2 (9.7) the predominant form will be the zwitterion (CH3CH(NH3+)(COO-)).

3) If the pH is upper the pKa2 of the amino group (9.7) the predominant form will be with the carboxyl group deprotonated, forming an anion (CH3CHNH2(COO-)).

8 0

2 years ago

Only one isotope of this element occurs in nature. one atom of this isotope has a mass of 9.123 ✕ 10-23 g. identify the element

o-na [289]

The atom has only one isotope which means 100 % of same atom is present in nature. The atomic mass of an element is the number of times an atom of that element is heavier than an atom of carbon taken as 12. Mass of one atom of that isotope is 9.123 ✕ 10⁻²³ g, so mass of one mole of atom that is Avogadro's number of atom is 6.023 X 10²³ X 9.123 X 10⁻²³ g=54.94 g = 55 g (approximate).

So, the atom having atomic mass 55 will be Cesium (Cs). Only one isotope of Cesium is stable in nature.

5 0

1 year ago

Read 2 more answers

Complete the sentences to explain why the molecule ch3f is polar.

Lelu [443]

A group of environmentalists were discussing the benefits and drawbacks associated with using fossil fuels. Which argument best fits the conversation?
Fossil fuels are cheaper than alternative forms of energy.Fossil fuel reserves will never be depleted.Fossil fuels are easily renewed. Fossil fuel use does not affect the environment.

8 0

2 years ago

Read 2 more answers

A quantity of 85.0 mL of 0.900 M HCl is mixed with 85.0 mL of 0.900 M KOH in a constantpressure calorimeter that has a heat capa

bogdanovich [222]

Explanation:

The given data is as follows.

$V_{1}$ = 85.0 ml, $M_{1}$ = 0.9 M

$V_{2}$ = 85.0 ml, $M_{1}$ = 0.9 M

Hence, number of moles of HCl and KOH will be the same because both the solutions have same volume and molarity.

So, No. of moles = Molarity × Volume

= $0.9 M \times 0.085 L$ (as 1 L = 1000 ml so, 85 ml = 0.085 L)

= 0.076 mol

As 1 mole gives 56.2 kJ/mol of heat of neutralization. Hence, calculate the heat of neutralization given by 0.076 moles as follows.

$56.2 kJ/mol \times 0.076 mol$

= 4.271 kJ

or, = 4271 J (as 1 kJ = 1000 J)

Therefore, heat released = - heat of gained by calorimeter

Since, it is given that density of the solution is similar to the density of water which is 1 g/ml.

Hence, mass of HCl = density × Volume of HCl

= 1.00 g/ml × 85.0 ml

= 85 g

Similarly, mass of KOH = = density × Volume of HCl

= 1.00 g/ml × 85.0 ml

= 85 g

Hence, total mass of the solution = 85 g + 85 g

= 170 g

Also, q = $mC \Delta T$

4271 J = $170 g \times 325 J/^{o}C \times (T_{f} - 18.24)^{o}C$

0.0773 = $T_{f} - 18.24$

$T_{f}$ = $18.317^{o}C$

Thus, we can conclude that final temperature of the mixed solution is $18.317^{o}C$ .

6 0

2 years ago

Why are weight and mass used synonymously on Earth?

RUDIKE [14]

Actually mass and weight are two different things but most people did not understand the difference between them. And they are used synonymously on the earth. Mass is the measure of the amount of matter and weight is the measure of how the force of gravity acts on the mass that is Weight = mass x force of gravity. And they are also directly proportional to each other that is also the reason both terms are used synonymously.

5 0

2 years ago

Read 2 more answers