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ivanzaharov [21]
3 years ago
5

Which half-reaction correctly represents reduction? *

Chemistry
1 answer:
nasty-shy [4]3 years ago
3 0

Answer:

C

Explanation:

Reduction can be seen through addition (gaining) of electrons, addition of Hydrogen or removal of Oxygen

Mn7+ is reduced to Mn4+ by the addition of 3 electrons.

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What is the % composition of Carbon in Chromium (iii) Carbonate
photoshop1234 [79]

Step 1 - Discovering the ionic formula of Chromium (III) Carbonate

Chromium (III) Carbonate is formed by the ionic bonding between Chromium (III) (Cr(3+)) and Carbonate (CO3(2-)):

Cr^{3+}+CO^{2-}_3\rightarrow Cr_2(CO_3)_3

Step 2 - Finding the molar mass of the substance

To find the molar mass, we need to multiply the molar mass of each element by the number of times it appears in the formula of the substance and, finally, sum it all up.

The molar masses are 12 g/mol for C; 16 g/mol for O and 52 g/mol for Cr. We have thus:

\begin{gathered} C\rightarrow3\times12=36 \\  \\ O\rightarrow9\times16=144 \\  \\ Cr\rightarrow2\times52=104 \end{gathered}

The molar mass will be thus:

M=36+104+144=284\text{ g/mol}

Step 3 - Finding the percent composition of carbon

As we saw in the previous step, the molar mass of Cr2(CO3)3 is 284 g/mol. From this molar mass, 36 g/mol come from C. We can set the following proportion:

\begin{gathered} 284\text{ g/mol ---- 100\%} \\ 36\text{ g/mol ----- x} \\  \\ x=\frac{36\times100}{284}=\frac{3600}{284}=12.7\text{ \%} \end{gathered}

The percent composition of Carbon is thus 12.7 %.

8 0
1 year ago
Ca(s)+2hno3(aq)→ca(no3)2(aq)+h2(g) identify the oxidizing agent.
aleksandr82 [10.1K]

To find for the oxidizing agent, first let us write the half reactions of this complete chemical reaction:

Ca = Ca2+ + 2e- <span>
2 H+ + 2e- = H2</span>

 

The oxidizing agent would be the substance of the element that is reduced. We know that an element is reduced when an electron is added to it. In this case, the element being reduced is H. Therefore the oxidizing agent is HNO3.

 

Answer:

<span>HNO3</span>

8 0
3 years ago
Read 2 more answers
What did Dalton's atomic theory contribute to science?
Serga [27]

Answer:

B

Explanation:

Pasted below is his 5 theory's and all of them are the building blocks of chemistry today.  

1. Matter is made up of atoms that are indivisible and indestructible.

2. All atoms of an element are identical.

3. Atoms of different elements have different weights and different chemical properties.

4. Atoms of different elements combine in simple whole numbers to form compounds.

5. Atoms cannot be created or destroyed. When a compound decomposes, the atoms are recovered unchanged.

4 0
3 years ago
HELP PLEASE
vodomira [7]

Answer:

4) how charged the object creating the field is and the distance between the two charged objects

3 0
3 years ago
A pure white crystalline compound was found to melt at 112.5-113.0oC when taken on a melting point apparatus, and on further hea
Sergeeva-Olga [200]

According to the question, the determined melting point of the compound is 112.5-113.0oC. When the solidified compound was retried, the melting point was found to be 133.6-154.5oC. This greater range higher than  112°C is caused by reusing samples leads to errors.

A pure sample is known by its sharp melting point. A pure sample does not melt over a large range. We can see this in the predetermined melting points of the pure sample(112.5-113.0oC).

However, reusing a sample introduces errors because the pure sample may become contaminated leading to a larger and higher range of melting point (133.6-154.5oC) which is far above  112°C.

Learn more: brainly.com/question/5325004

8 0
2 years ago
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