The normal boiling point for h2se is higher than the normal boiling point for h2s . this can be explained by

What is the atomic mass of one mole of H? g/mole

Oksanka [162]

For one mole of hydrogen, H, the atomic mass is 1 g per mole. Hydrogen contains 1 proton and zero neuton. A neutral atom of hydrigen also contains 1 electron.

7 0

2 years ago

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Solid chromium (III) reacts with oxygen gas to form solid Cr2O3. What is this type of reaction?

mafiozo [28]

Answer:

.081 g of O2

Explanation:

4Cr + 3O2 -----> 2Cr2O3

.175 g Cr x [1 mole / 52.0 g] x [2 moles Cr2O3 / 4 moles Cr] x [152 g / 1 mole] = .256 g of Cr2O3

.175 g Cr x [1 mole / 52.0 g] x [3 moles O2 / 4 moles Cr] x [32 g / 1 mole] = .081 g of O2

5 0

2 years ago

What is true about protons within an atom?

Ira Lisetskai [31]

It defines the element. If you change the protons, you change the type of element. A proton is positively charged and is most of the mass of the atom, next to the neutron. Neutrons have a very very very slightly higher mass.

4 0

3 years ago

Aqueous solutions of Na2CO3 and Ca(NO3)2, 0.10 M each, are combined. A white precipitate is observed in the container after mixi

anzhelika [568]

The question is incomplete. Here is the complete question.

Aqueous solutions of $Na_{2}CO_{3}$ and $Ca(NO_{3})_{2}$ , 0.10 M each, are combined. A white precipitate is observed in the container after mixing. he precipitate is filtered andcarefully rinsed with distilled water to remove other ions. A sample of the precipitate is added to 100 mL of 0.1 M NaCl. A second sample of the precipitate is then added to 100 mL of 0.1 M HCl. What would be observed in each case?

Observation upon Observation upon

addition of precipitate addition of precipitate

to NaCl(aq) to HCl(aq)

(A) additional precipitates forms no visible reaction occurs

(B) no visible reaction occurs gas is produced and some precipitate dissolves

(C) no visible reaction occurs no visible reaction occurs

(D) additional precipitates forms gas is produced and some

precipitate dissolves

Answer: (B) No visible reaction occurs; Gas is produced and some precipitate dissolves

Explanation: When aqueous solutions of $Na_{2}CO_{3}$ and $Ca(NO_{3})_{2}$ are combined, it reacts according to the following balanced equation:

$Na_{2}CO_{3}+Ca(NO_{3})_{2}$ → $CaCO_{3}_{(s)}+2NaNO_{3}_{(aq)}$

forming calcium carbonate ( $CaCO_{3}$ ), which, as it is insoluble in water, precipitates as a solid of the color white. This process is Precipitation and this reaction is a Precipitation Reaction.

When calcium carbonate reacts with NaCl it produces:

$CaCO_{3}+2NaCl$ → $CaCl_{2}+Na_{2}CO_{3}$

Now, calcium chloride is an inorganic compound very soluble in water, so, in this reaction, there are no precipitate and no visible reaction occurs.

When $CaCO_{3}$ reacts with hydrochloridric acid, the balanced reaction is

$CaCO_{3}+2HCl$ → $CaCl_{2}+H_{2}CO_{3}$

which, also produces calcium chloride and carbonic acid.

Both are soluble in water but, when carbonic acid is in an "aqueous state", carbonic acid, it dissociates, forming carbon dioxide and water. Therefore, gas is produced and some precipitate dissolves.

In conclusion, sentence B is the correct alternative.

5 0

3 years ago

Diagram of the outermost shell of fluorine atom?

Rufina [12.5K]

Orbital diagram:

$\text{Energy}\left \uparrow \begin{array}{ccccc}2p & &\uparrow\downarrow&\uparrow\downarrow&\uparrow\\2s&\uparrow\downarrow\end{array}\right.$

<h3>Explanation</h3>

Fluorine F is found in the second column from the right end of a modern periodic table. Fluorine is next to and on the left of the noble gas element neon. A neutral fluorine atom is one electron short of neon, which contains 8 electrons in the outermost shell when neutral. As a result, there are 7 electrons in the outermost shell of a fluorine atom.

Fluorine is in period 2. Its electrons occupy two main shells. The second main shell is the outermost shell of F. There are two subshells in the second main shell:

2s, which holds up to two electrons, and
2p, which holds up to six electrons.

A 2s electron carries less energy than a 2p electron. By Aufbau principle, the seven electrons will fill the two spaces in 2s before moving on the 2p. Among the 7 outermost shell electrons, $7 - 2 = 5$ will end up going to 2p.

The only 2s orbital is filled with two electrons. The two 2s electrons will pair up with opposite spins, as seen with the two arrows. Two of the 2p orbitals will contain two electrons. Those electrons will also pair up. The third 2p orbital will contain only one electron. That electron can spin either $\uparrow$ or $\downarrow$ . Here that electron is shown as an upward arrow.

3 0

2 years ago

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