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jarptica [38.1K]
3 years ago
15

Answer all the following questions by putting a circle around a letter A.B.C or D

Chemistry
1 answer:
Nataly_w [17]3 years ago
3 0

Answer:

C. 21%oxygen

Explanation:

Dry air contains 78.09% nitrogen, 20.95%oxygen, 0.93% argon, 0.04% carbon dioxide, and small amounts of other gases.

You might be interested in
Organelles_____are specialized structures that carry out particular jobs and functions?
sergejj [24]

Answer:

Cell or cellular

Explanation:

Heyy!! Not sure, but cell and cellular are the same. They carry out particular jobs and functions. Hope this helps, thank you :) !!

7 0
3 years ago
When 2 moles of Fe(s) react with Cl2(g) to form FeCl3(s) according to the following equation, 799 kJ of energy are evolved.
GenaCL600 [577]

Answer:

1. Exothermic.

2. -1598 kJ.

Explanation:

Hello!

1. In this case, according to the reaction, we can infer that 799 kJ of energy are evolved (given off, released) it means that the enthalpy of reaction is negative as the reactants have more energy than the products; which means this is an exothermic reaction.

2. Here, as we know that the enthalpy of reaction is -799 kJ/mol, we can compute the q-value as shown below, considering the reacted 2 moles of solid iron:

q=2mol*-799 kJ/mol\\\\q=-1598kJ

Which means that 1598 kJ of energy are evolved when 2 moles of solid iron react.

Best regards!

4 0
3 years ago
Calculate the Molarity when a 6.11 mL solution of 0.1 H2SO4 is diluted with 105.12 mL of water
barxatty [35]

Molarity after dilution : 0.0058 M

<h3>Further explanation </h3>

The number of moles before and after dilution is the same  

The dilution formula

 M₁V₁=M₂V₂

M₁ = Molarity of the solution before dilution  

V₁ = volume of the solution before dilution  

M₂ = Molarity of the solution after dilution  

V₂ = Molarity volume of the solution after dilution

M₁=0.1 M

V₁=6.11

V₂=105.12

\tt M_2=\dfrac{M_1.V_1}{V_2}=\dfrac{0.1\times 6.11}{105.12}=0.0058~M

5 0
3 years ago
Report the number 315.05 to 3 significant figures.
emmainna [20.7K]

Answer:

315.

Explanation:

Hello.

In this case, since the given number has five significant figures as the zero is to the right of the first nonzero digit (3), if it is required to report it with three significant figures, it is necessary to "cut" it at the first five without any rounding since the subsequent zero is less than five.

Thus the number turns out:

315

Best regards.

5 0
4 years ago
What is reduction potential?​
Shtirlitz [24]

Answer:

A reduction potential measures the tendency of a molecule to be reduced by taking up new electrons. ... Standard reduction potentials can be useful in determining the directionality of a reaction. The reduction potential of a given species can be considered to be the negative of the oxidation potential.

Explanation:

8 0
3 years ago
Read 2 more answers
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