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2 years ago

Approximately, how many national parks are there in the United States? a. 25 b. 50 c. 120 d. 474

Chemistry

2 answers:

Len [333]2 years ago

7 0

B, I would believe. There are 58, but B is the closest we can get.

Art [367]2 years ago

3 0

The correct answer is - b. 50.

The United States have approximately 50 national parks, or to be more specific, there's 58 of them on the territory of this vast North American country. One of the best known and most visited parks that are a global tourist attraction are the Yellowstone National Park, The Grand Canyon National Park, and the Yosemite National Park. There are also many national parks in the United States that we can easily say are underrated and are in the shadow of these three, but at least that is good for the nature because the less people are visiting them, the less damage will be done to them.

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Answer:

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Recall the two conceptual steps necessary to dissolve a solute and form a solution

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3 years ago

When a chemical reaction destroys a solid

bogdanovich [222]

Answer:

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2 years ago

Suppose that a certain biologically important reaction is quite slow at physiological temperature (37 oC) in the absence of a ca

Oksi-84 [34.3K]

Answer:

30 kJ

Explanation:

Arrhenius equation is given by:

$k=Aexp(-Ea/RT)\\$

Here, k is rate constant, A is Pre-exponential factor, Ea is activation energy and T is temperature.

taking natural log of both side

ln k = ln A - Ea/RT

In Arrhenius equation, A, R and T are constant.

Therefore,

$ln\frac{k_2}{k_1} =\frac{Ea_1-Ea_2}{RT}$

$Ea_1-Ea_2$ is the lowering in activation energy by enzyme,

R = 8.314 J/mol.K

T = 37°C + 273.15 = 310 K

$\frac{k_2}{k_1} =1\times 10^5$

$ln 1\times 10^5 =\frac{Ea_1-Ea_2}{RT}\\{Ea_1-Ea_2} = 11.512 \times 8.314 \times 310\\=29670\ J\\=30\ kJ$

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3 years ago

A sample of a compound is analyzed and found to contain 0.420 g nitrogen, 0.480g oxygen, 0.540 g carbon and 0.135 g hydrogen. Wh

RSB [31]

Answer:

C2H5NO

Explanation:

constituent elements N O C H

Mass composition 0.420 0.480 0.540 0.135

mole ratio 0.42/14 0.48/16 0.54/12 0.135/1

= 0.03 0.03 0.045 0.135

dividing by the smallest 0.03/0.03 0.03/0.03 0.045/0.03 0.135/0.03

ratio = 1 1 1.5 4.5

= 1 1 2 5

EMPERICAL FORMULA = C2H5NO

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2 years ago