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3 years ago

How many moles are in 7.00E24 atoms of Ca?

Chemistry

1 answer:

iris [78.8K]3 years ago

3 0

Explanation:

In chemistry, a mole is the base unit of the amount of substance in a system containing elementary entities (atoms, molecules, ions, electrons), and one mole of substance corresponds to the Avogadro's constant or $6.023 \ \times \ 10^{23}$ entities. The stoichiometry equation that relates the amount of substance into the measurement in moles is

$n \ = \ \displaystyle\frac{\alpha}{N_{A}}$ ,

where $n$ is the number of moles, $\alpha$ is the amount of substance and $N_{A}$ is the Avogadro's constant.

Therefore,

$n \ = \ \displaystyle\frac{7.00 \ \times \ 10^{24} \ \text{atoms}}{6.023 \ \times \ 10^{23} \ \text{atoms mol}^{-1}} \\ \\ n \ = \ 11.624 \ \text{mol}$ .

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Bromine pentachloride formula

nekit [7.7K]

Answer:

Bromine pentafluoride, BrF5

bromine pentafluoride is an interhalogen compound and a fluoride of bromine. It is a strong fluorination reagent. BrF5 finds use in oxygen isotope analysis.

4 0

3 years ago

List two general properties of molecular compounds

Katen [24]

Low melting points and boiling points. ...Low enthalpies of fusion and vaporization These properties are usually one or two orders of magnitude smaller than they are for ionic compounds.Soft or brittle solid forms. ...Poor electrical and thermal conductivity.

5 0

3 years ago

Explain why vanadium (radius=134 pm) and copper (radius=128 pm) have nearly identical atomic radii, even though the atomic numbe

Viktor [21]

<span>There are few main factors affecting the atomic radii, the outermost electrons and the protons in the nucleus and also the shielding of the internal electrons. I would speculate that the difference in radii is given by the electron clouds since the electrons difference in these two elements is in the d orbital and both has at least 1 electron in the 4s (this 4s electron is the outermost electron in all the transition metals of this period). The atomic radio will be mostly dependent of these 4s electrons than in the d electrons. Besides that, you can see that increasing the atomic number will increase the number of protons in the nucleus decreasing the ratio of the atoms along a period. The Cu is an exception and will accommodate one of the 4s electrons in the p orbital.

</span><span>Regarding the density you can find the density of Cu = 8.96g/cm3 and vanadium = 6.0g/cm3. This also correlates with the idea that if these two atoms have similar volume and one has more mass (more protons; density is the relationship between m/V), then a bigger mass for a similar volume will result in a bigger density.</span>

7 0

3 years ago

An adult mosquitoes lifespan is about 16 days how many minutes is that

AVprozaik [17]

The answer is 23, 040 minutes. To solve this you can start by changing days in to hours. We know that there are 24 hours in a day. To find how many hours are in 16 days you multiply 24 by 16 which is 384. Next you must find out how many minutes are in 384 hours. we know there are 60 minutes per hour. To find how many minutes are in 384 hours, you multiply 384 by 60. To this you get 23, 040 which is your answer.

3 0

3 years ago

I was checking my answers for a chem test and came across a solution for a problem where the ∆S was pos, ∆H was neg and ∆G was n

nevsk [136]

Answer:

there is only 15 points

Explanation:

The second law of thermodynamics says that the entropy of the universe always increases for a spontaneous process: \Delta \text {S}_{\text{universe}}=\Delta \text {S}_{\text{system}} + \Delta \text {S}_{\text{surroundings}} > 0ΔS

universe

=ΔS

system

+ΔS

surroundings

>0delta, start text, S, end text, start subscript, start text, u, n, i, v, e, r, s, e, end text, end subscript, equals, delta, start text, S, end text, start subscript, start text, s, y, s, t, e, m, end text, end subscript, plus, delta, start text, S, end text, start subscript, start text, s, u, r, r, o, u, n, d, i, n, g, s, end text, end subscript, is greater than, 0

At constant temperature and pressure, the change in Gibbs free energy is defined as \Delta \text G = \Delta \text H - \text{T}\Delta \text SΔG=ΔH−TΔSdelta, start text, G, end text, equals, delta, start text, H, end text, minus, start text, T, end text, delta, start text, S, end text.

When \Delta \text GΔGdelta, start text, G, end text is negative, a process will proceed spontaneously and is referred to as exergonic.

The spontaneity of a process can depend on the temperature.

Spontaneous processes

In chemistry, a spontaneous processes is one that occurs without the addition of external energy. A spontaneous process may take place quickly or slowly, because spontaneity is not related to kinetics or reaction rate. A classic example is the process of carbon in the form of a diamond turning into graphite, which can be written as the following reaction:

8 0

3 years ago