What is the simplest type of pure substance

Which equation is correctly balanced?

ludmilkaskok [199]

Answer:

C) 2 H₂ + O₂ → 2 H₂O

Explanation:

4 atoms of hydrogen on reactant side

2 atoms of oxygen on reactant side

4 atoms of hydrogen on product side

2 atoms of oxygen on product side

6 0

3 years ago

Some covalent compounds contain atoms of just one element. true or false?

kifflom [539]

True, because diatomic elements (H2, O2, F2, Br2, I2, N2, Cl2) consist of only one element but are molecules with covalent bonds.

6 0

4 years ago

Olympic cyclist fill their tires with helium to make them lighter. Calculate the mass of air in an air filled tire and the mass

inn [45]

<u>Answer:</u> The mass difference between the two is 7.38 grams.

<u>Explanation:</u>

To calculate the number of moles, we use the equation given by ideal gas follows:

$PV=nRT$

where,

P = pressure = 125 psi = 8.50 atm (Conversion factor: 1 atm = 14.7 psi)

V = Volume = 855 mL = 0.855 L (Conversion factor: 1 L = 1000 mL)

T = Temperature = $25^oC=[25+273]K=298K$

R = Gas constant = $0.0821\text{ L. atm }mol^{-1}K^{-1}$

n = number of moles = ?

Putting values in above equation, we get:

$8.50atm\times 0.855L=n\times 0.0821\text{ L atm }mol^{-1}K^{-1}\times 298K\\\\n=\frac{8.50\times 0.855}{0.0821\times 298}=0.297mol$

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ .....(1)

<u>For air:</u>

Moles of air = 0.297 moles

Average molar mass of air = 28.8 g/mol

Putting values in equation 1, we get:

$0.297mol=\frac{\text{Mass of air}}{28.8g/mol}\\\\\text{Mass of air}=(0.297mol\times 28.8g/mol)=8.56g$

Mass of air, $m_1$ = 8.56 g

<u>For helium gas:</u>

Moles of helium = 0.297 moles

Molar mass of helium = 4 g/mol

Putting values in equation 1, we get:

$0.297mol=\frac{\text{Mass of helium}}{4g/mol}\\\\\text{Mass of helium}=(0.297mol\times 4g/mol)=1.18g$

Mass of helium, $m_2$ = 1.18 g

Calculating the mass difference between the two:

$\Delta m=m_1-m_2$

$\Delta m=(8.56-1.18)g=7.38g$

Hence, the mass difference between the two is 7.38 grams.

5 0

3 years ago

_________ refers to the total energy of a system.

inna [77]

Enthalpy refers to the total energy of a system. Hope this helped!

3 0

4 years ago

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What will most likely happen in the absence of a cell membrane?

Zielflug [23.3K]

<h2>Answer:</h2>

The correct answer is option D which is substances will pass in and out of the cell in an uncontrolled manner.

<h3>Explanation:</h3>

Cell membrane is outer organelle in the cell, it is responsible for the transport of materials into and out to the cell through osmosis and active transport.
In the absence of the cell membrane, there will not be control of transport of a materials to the cell.
Energy production is the task of mitochondria and food storage is the function of vacuoles.
Photosynthesis takes place on the chloroplasts.

3 0

3 years ago

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