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3 years ago

2. Which types of changes observe the law of

Chemistry

1 answer:

mart [117]3 years ago

3 0

D) physical and chemical changes

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In which process are simple materials chemically combined to form more complex materials?

allsm [11]

Answer:

A) synthesis

I hope this helps!

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2 years ago

If you sprayed an air freshener, where would the highest concentration of air freshener be found?

Hunter-Best [27]

FLOOR. Most of the molecules that dont sick to something fall on the floor so most would be on the FLOOR.

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2 years ago

2NO + 3MnO2 + 4H â 2NO3- + 3Mn2 + 2H2O For the above redox reaction, assign oxidation numbers and use them to identify the eleme

mixer [17]

Answer:

Manganese decreases from 4+ to 2+ (reduced and oxidizing agent) and nitrogen increases from 2+ to 5+ (oxidized and reducing agent).

Explanation:

Hello there!

In this case, according to the given redox reaction, we rewrite it as a convenient first step:

$2NO + 3MnO_2 + 4H^+ \rightarrow 2NO_3^- + 3Mn^{2+} + 2H_2O$

Next, we assign the oxidation numbers as follows:

$2N^{2+}O^{2-} + 3Mn^{4+}O^{-2}_2 + 4H^+ \rightarrow 2(N^{5+}O^{2-}_3)^- + 3Mn^{2+} + 2H^+_2O^{2-}$

Thus, we can see that both manganese and nitrogen undergo a change in their oxidation number, the former decreases from 4+ to 2+ (reduced and oxidizing agent) and the latter increases from 2+ to 5+ (oxidized and reducing agent).

Regards!

4 0

2 years ago

Is an oreo a pure substance or a mixture and why?

pav-90 [236]

Pure oreo would be a mixture

7 0

3 years ago

What is the molarity of a solution in which 250 grams of NaCl are dissolved in 2.9 L of water?

Maksim231197 [3]

Answer:

About 1.48 M.

Explanation:

The formula for molarity is mol/L.

So firstly, you must find the amount of moles in 250 grams of NaCl.

I do this by using stoichiometry. First, I find how nany grams are in a single mole of NaCl. This is around 58.44 grams/mole. Now that I know this, I can now use a stoich table. (250 g NaCl * 1 mol NaCl / 58.44 g NaCl). I plug this into my calculator.

I get that 250 grams of NaCl is equal to about 4.28 moles.

Now I just plug into the formula!

4.28 moles/2.9 L = about 1.48

I've attached a picture of my personal notes below which shows work I have done in similar equations.

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1 year ago