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3 years ago

The number of carbon atoms in 45.21g C

Chemistry

1 answer:

Inga [223]3 years ago

7 0

Answer:

2.26 X10^24 carbon atoms

Explanation:

The number of carbon atoms in 45.21g C

carbon has an atomic mas of 12.01 gm

45.21 g has 45.21/12.01 = 3.76 moles of C

a mole contains Avogadros number of particles

6.022 X 10^23

3.76 moles contain 3.76 X6,022 X 10^23 =

2.26 X10^24 carbon atoms

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Which of the following statements is incorrect? Group of answer choices The product of wavelength and frequency of electromagnet

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Answer: Option (b) is the correct.

Explanation:

It is known that energy is directly proportional to frequency.

Mathematically, $E \propto \nu$

or, E = $h \times \nu$ ............ (1)

where, E = energy

h = Plank's constant

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This relation shows that higher is the energy then more will be the frequency of electrmagnetic radiation.

Also, $\nu = \frac{c}{\lambda}$ ......... (2)

where, c = speed of light

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Therefore, substituting value of $\nu$ from equation (2) into equation (1) as follows.

E = $h \times \nu$

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If water and oil are combine If water and oil are combined in a container, the resulting liquid is a(n) A. solution. B. mixture.

mart [117]

B. Mixture is the answer

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3 years ago

A mixture of carbon dioxide and helium gases is maintained in a 7.91 L flask at a pressure of 1.42 atm and a temperature of 33 °

Crank

Answer:

The gas mixture contains 1.038 grams of helium

Explanation:

Step 1: Data given

Volume of the flask = 7.91 L

Total Pressure = 1.42 atm

Temperature = 33 °C

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Step 2: Calculate total number moles of gas

p*V = n*R*T

⇒ p = the pressure = 1.42 atm

⇒ V = the volume = 7.91 L

⇒ n= the number of moles = TO BE DETERMINED

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⇒ T = the temperature = 33 °C = 306 Kelvin

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n = 0.447 moles

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Moles CO2 = mass CO2 / Molar mass CO2

Moles CO2 = 8.25 grams / 44.01 g/mol

Moles CO2 = 0.1875 moles

Step 4: Calculate moles of Helium

Moles Helium = total moles of gas - moles of CO2

Moles Helium = 0.447 - 0.1875 = 0.2595 moles of helium

Step 5: Calculate mass of helium

Mass of helium = moles of helium * molar mass of helium

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3 years ago

A gravel can be broken down into different kinds of substances by physical processes. No chemical reactions are needed to separa

Vlada [557]

Answer:

MIXTURE

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If 4.0 g of helium gas occupies a volume of 22.4 L at 0 o C and a pressure of 1.0 atm, what volume does 3.0 g of He occupy under

WINSTONCH [101]

Answer:

the volume occupied by 3.0 g of the gas is 16.8 L.

Explanation:

Given;

initial reacting mass of the helium gas, m₁ = 4.0 g

volume occupied by the helium gas, V = 22.4 L

pressure of the gas, P = 1 .0 atm

temperature of the gas, T = 0⁰C = 273 K

atomic mass of helium gas, M = 4.0 g/mol

initial number of moles of the gas is calculated as follows;

$n_1 = \frac{m_1}{M} \\\\n_1 = \frac{4}{4} = 1$

The number of moles of the gas when the reacting mass is 3.0 g;

m₂ = 3.0 g

$n_2 = \frac{m_2}{M} \\\\n_2 = \frac{3}{4} \\\\n_2 = 0.75 \ mol$

The volume of the gas at 0.75 mol is determined using ideal gas law;

PV = nRT

$PV = nRT\\\\\frac{V}{n} = \frac{RT}{P} \\\\since, \ \frac{RT}{P} \ is \ constant,\ then;\\\frac{V_1}{n_1} = \frac{V_2}{n_2} \\\\V_2 = \frac{V_1n_2}{n_1} \\\\V_2 = \frac{22.4 \times 0.75}{1} \\\\V_2 = 16.8 \ L$

Therefore, the volume occupied by 3.0 g of the gas is 16.8 L.

4 0

3 years ago