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3 years ago

A chemist weighed out 20.7 g of sodium . Calculate the number of moles of sodium she weighed out

Chemistry

1 answer:

Pachacha [2.7K]3 years ago

8 0

Answer:

about 0.9 mol

Explanation:

there are 22.990 g/mol of Na

20.7/22.99 = 0.900391 mol

about 0.9 mol

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Chlorophyll a is one of the green pigments found in plants. Chlorophyll a has the molecular formula C55H72MgN4O5. How many atoms

algol13

The number of atoms in a molecule can be calculated by adding all of the number of elements from the chemical formula. For chlorophyll, the chemical formula would be C55H72MgN4O5 adding all the elements we have 137 atoms. Hope this answers the question.

8 0

3 years ago

PLEASe help. How many ions? With picture.

Likurg_2 [28]

Since this equation is balanced, we know that the law of conversation of mass id applied, and we could calculate easily.

Na= 2
NO3= 2
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Cl= 1

5 0

3 years ago

Under standard-state conditions, which of the following species is the best reducing agent? a. Ag+ b. Pb c. H2 d. Ag e. Mg2+

eimsori [14]

Answer: The correct answer is Option b.

Explanation:

Reducing agents are defined as the agents which help the other substance to get reduced and itself gets oxidized. They undergo oxidation reaction.

$X\rightarrow X^{n+}+ne^-$

For determination of reducing agents, we will look at the oxidation potentials of the substance. Oxidation potentials can be determined by reversing the standard reduction potentials.

For the given options:

Option a: $Ag^+$

This ion cannot be further oxidized because +1 is the most stable oxidation state of silver.

Option b: $Pb$

This metal can easily get oxidized to $Pb^{2+}$ ion and the standard oxidation potential for this is 0.13 V

$Pb\rightarrow Pb^{2+}+2e^-;E^o_{(Pb/Pb^{2+})}=+0.13V$

Option c: $H_2$

This metal can easily get oxidized to $H^{+}$ ion and the standard oxidation potential for this is 0.0 V

$H_2\rightarrow 2H^++2e^-;E^o_{(H_2/H^{+})}=0.0V$

Option d: $Ag$

This metal can easily get oxidized to $Ag^{+}$ ion and the standard oxidation potential for this is -0.80 V

$Ag\rightarrow Ag^{+}+e^-;E^o_{(Ag/Ag^{+})}=-0.80V$

Option e: $Mg^{2+}$

This ion cannot be further oxidized because +2 is the most stable oxidation state of magnesium.

By looking at the standard oxidation potential of the substances, the substance having highest positive $E^o$ potential will always get oxidized and will undergo oxidation reaction. Thus, considered as strong reducing agent.

From the above values, the correct answer is Option b.

8 0

3 years ago

(((NEED ANSWER QUICK!!!))) Which is the stronger conjugate base, CN- or OCN-? Explain

Shkiper50 [21]

Answer:

The stronger conjugate base will be the weaker acid; i.e., the acid with the smaller Ka-value.

Explanation:

Given conjugate base CN⁻ => weak acid => HCN => Ka =4.9 x 10⁻¹⁰

Given conjugate base OCN⁻ => weak acid=> HOCN => Ka = 3.5 x 10⁻⁴

Ka(HCN) << Ka(HOCN) => CN⁻ is a much stronger conjugate base than OCN⁻

6 0

3 years ago

(only reply if you know the answer or get reported) Please solve this ty

kolezko [41]

Answer:

7) 50 8)4

Explanation:

I answered the question what do you want to gave me

4 0

3 years ago