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3 years ago

What is special about nitrogen , and what is its main function in the atmosphere

1 answer:

5 0

Nitrogen makes about 78% of the air we breathe. Nitrogen is extremely important in living things. It forms the building blocks of proteins. We need proteins because they make up our skin and hair. Proteins also help us digest food. We get our nitrogen from plants, and plants get it from bacteria in the soil. Our atmosphere provides life with the nitrogen it needs.

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Collisions may occur between tectonic plates. The resulting geological features differ depending on whether the colliding plates

nika2105 [10]

B. Amid - ocean ridge is formed

8 0

2 years ago

A chemistry student needs to standardize a fresh solution of sodium hydroxide. He carefully weighs out 28.mg of oxalic acid H2C2

Nezavi [6.7K]

Answer:

The molarity of the student's sodium hydroxide solution is 0.0219 M

Explanation:

1) Chemical reaction.

a) Kind of reaction: neutralization

b) General form: acid + base → salt + water

c) Word equation:

sodium hydroxide + oxalic acid → sodium oxalate + water

d) Chemical equation:

NaOH + H₂C₂O₄ → Na₂C₂O₄ + H₂O

b) Balanced chemical equation:

2NaOH + H₂C₂O₄ → Na₂C₂O₄ + 2H₂O

2) Mole ratio

2mol Na OH : 1 mol H₂C₂O₄ :1 mol Na₂C₂O₄ : 2 mol H₂O

3) Starting amount of oxalic acid

mass = 28 mg = 0.028 g
molar mass = 90.03 g/mol
Convert mass in grams to number of moles, n:

n = mass in grams / molar mass = 0.028 g / 90.03 g/mol = 0.000311 mol

4) Titration

Volume of base: 28.4 mL = 0.0248 liter
Concentration of base: x (unknwon)

Number of moles of acid: 2.52 mol (calculated above)

Proportion using the theoretical mole ratio (2mol Na OH : 1 mol H₂C₂O₄)

$\frac{2}{1} =\frac{x}{2.52}\\ \\ \\x=0.000311(2)=0.000622$

That means that there are 0.000622 moles of NaOH (solute)

5) Molarity of NaOH solution

M = n / V (liter) = 0.000622 mol / 0.0284 liter = 0.0219 M

That is the correct number using three signficant figures, such as the starting data are reported.

5 0

2 years ago

Read 2 more answers

PLEASE HELP!!

REY [17]

The physical properties of water is that it is clear, it has no taste. No odour. It freezes at 0 degrees Celsius and boils at 100 degrees Celsius. The different stages of water is liquid, solid and gas. It is liquid at normal state. Ice when solid and steam when it is a gas state.

It is essential for human life because majority of the human body is made out of water. The water in the body allows certain parts and organs to function properly. Without water humans are most like to become I’ll and even dehydrate causing major injuries. It is also essential for the brain to function

3 0

2 years ago

Distinguish and give example for homogeneous and heterogeneous mixture

Nataliya [291]

Answer:

Through combining two or more substances, a mixture is produced. A homogeneous solution tends to be identical, no matter how you sample it. Homogeneous mixtures are sources of water, saline solution, some alloys, and bitumen. Sand, oil and water, and chicken noodle soup are examples of heterogeneous mixtures.

Explanation:

6 0

2 years ago

An atom of Iron has at least three different isotopes. What is the difference between an isotope of 55Fe and an isotope of 58Fe?

11Alexandr11 [23.1K]

The isotopes 55Fe and 58Fe are both Iron, but have a different atomic mass due to the added number of neutrons. Both isotopes have 26 protons, but 55Fe has more neutrons.

6 0

2 years ago