Molecular iodine, I2(g), dissociates into iodine atoms at 625 K with a first-order rate constant of 0.271 s−1 .

Give an example of how each compound is used or found in nature. Be sure to use complete sentences.

puteri [66]

Water is found in lakes and rivers. Its purpose in nature is to hydrate animals

Hydrogen gas is not abundant in nature, but hydrogen is abundant in water. Hydrogen (bonds) help ice float. Otherwise, freezing lakes would kill animals (it actually doesn't since the ice creates a "coat" above the water").

Ammonia is nitrogen-rich molecules that plant uses to get their nitrogen. It comes from the part of the nitrogen cycle where dead plants and animals are decayed.

Carbon dioxide is what we exhale. Plants "inhale" carbon dioxide and use that for photosynthesis.

Hydrogen sulfide is emitted by volcanoes and by anaerobic (oxygen-less) decay from bacteria.

Have an awesome day! I hope this helps.

8 0

3 years ago

Hello, everyone!

marusya05 [52]

Answer: 27.09 ppm and 0.003 %.

First, for air pollutants, ppm refers to parts of steam or gas per million parts of contaminated air, which can be expressed as cm³ / m³. Therefore, we must find the volume of CO that represents 35 mg of this gas at a temperature of -30 ° C and a pressure of 0.92 atm.

Note: we consider 35 mg since this is the acceptable hourly average concentration of CO per cubic meter m³ of contaminated air established in the "National Ambient Air Quality Objectives". The volume of these 35 mg of gas will change according to the atmospheric conditions in which they are.

So, according to the law of ideal gases,

PV = nRT

where P, V, n and T are the pressure, volume, moles and temperature of the gas in question while R is the constant gas (0.082057 atm L / mol K)

The moles of CO will be,

n = 35 mg x $\frac{1 g}{1000 mg}$ x $\frac{1 mol}{28.01 g}$

→ n = 0.00125 mol

We clear V from the equation and substitute P = 0.92 atm and

T = -30 ° C + 273.15 K = 243.15 K

V = $\frac{0.00125 mol x 0.082057 \frac{atm L}{mol K} x 243 K}{0.92 atm}$

→ V = 0.0271 L

As 1000 cm³ = 1 L then,

V = 0.0271 L x $\frac{1000 cm^{3} }{1 L}$ = 27.09 cm³

Then the acceptable concentration c of CO in ppm is,

c = 27 cm³ / m³ = 27 ppm

To express this concentration in percent by volume we must consider that 1 000 000 cm³ = 1 m³ to convert 27.09 cm³ in m³ and multiply the result by 100%:

c = 27.09 $\frac{cm^{3} }{m^{3} }$ x $\frac{1 m^{3} }{1 000 000 cm^{3} }$ x 100%

c = 0.003 %

So, the acceptable concentration of CO if the temperature is -30 °C and pressure is 0.92 atm in ppm and as a percent by volume is 27.09 ppm and 0.003 %.

5 0

2 years ago

1. If I have 45 L of He in a balloon at 25 degrees celsius and increase the temperature of the

Greeley [361]

Use Charles' Law: V1/T1 = V2/T2. We assume the pressure and mass of the helium is constant. The units for temperature must be in Kelvin to use this equation (x °C = x + 273.15 K).

We want to solve for the new volume after the temperature is increased from 25 °C (298.15 K) to 55 °C (328.15 K). Since the volume and temperature of a gas at a constant pressure are directly proportional to each other, we should expect the new volume of the balloon to be greater than the initial 45 L.

Rearranging Charles' Law to solve for V2, we get V2 = V1T2/T1.

(45 L)(328.15 K)/(298.15 K) = 49.5 ≈ 50 L (if we're considering sig figs).

7 0

2 years ago

calculate the number of coulombs of positive charge in 250cm 3 of (neutral) water. (hint: a hydrogen atom contains one proton; a

Sidana [21]

Number of coulombs of positive charge in 250cm^3 water is 1.3×10^7 C

The volume of 250 cm^3 corresponds to a mass of 250 g since the density of water is 1.0 g/cm^3

This mass corresponds to 250/18 = 14 moles since the molar mass of water is 18. There are ten proton (each with charge q = +e) in each molecule of $H_{2}O$ So,

Q = 14NA q =14(6.02×10^23)(10)(1.60×10^−19C) = 1.3×10^7 C.

Mass is the quantity of matter in a physical body. It is also a measure of the body's inertia, the resistance to acceleration when a net force is applied. An object's mass also determines the strength of its gravitational attraction to other bodies.

Learn more about mass here:

brainly.com/question/17067547

#SPJ4

3 0

1 year ago

What is the percent composition of carbon in heptane c7h16

Gnom [1K]

Answer: the percent composition of carbon in heptane is 83.9%

Explanation:

1) Atomic masses of the atoms:

C: 12.01 g/mol

H: 1.008 g/mol

2) Molar mass of heptane:

C₇H₁₆: 7 × 12.01 g/mol + 16×1.008 g/mol = 100.2 g/mol

3) Mass of carbon in one mole of heptane:

C₇: 7 × 12.01 g/mol = 84.07 g/mol

3) Percent composition of carbon:

% = (mass in grams of C) / (mass in grams of C₇H₁₆) × 100 =

= (84.07 g/ 100.2 g) × 100 = 83.9% ← answer

8 0

3 years ago