Can someone help me plz!!!

Calculate the mass, in grams, of 2 moles of CaCl2.

Answer:

8g

Explanation:

1mole of oxygen -->2moles MgO

32g --> 80g

?g --> 20g

(20x32)÷80

= 8g oxygen

Answer:

Mass of oxygen needed  = 8 g

Explanation:

Given data:

Mass of oxygen needed = ?

Mass of MgO formed  = 20 g

Solution:

Chemical equation:

2Mg + O₂     →    2MgO

Number of moles of MgO:

Number of moles = mass/molar mass

Number of moles = 20 g/ 40 g/mol

Number of moles = 0.5 mol

Now we will compare the moles of MgO and O₂:

                        MgO         :            O₂

                           2            :            1

                          0.5          :        1/2×0.5 = 0.25 mol

Mass of oxygen needed:

Mass = number of moles × molar mass

Mass = 0.25 mol × 32 g/mol

Mass = 8 g

Answer:

0.78× 10 ²³ molecules

Explanation:

Given data:

Mass of pyridine = 10.35 g

Number of molecules = ?

Solution:

Number of moles of pyridine:

Number of moles = mass/molar mass

Number of moles = 10.35 g/ 79.1 g/mol

Number of moles = 0.13 mol

Number of molecules;

1 mole contain 6.022× 10 ²³ molecules

0.13 mol × 6.022× 10 ²³ molecules / 1mol

0.78× 10 ²³ molecules

Answer:

cause of climate change: The earth's climate is affected and changed through a lot of natural causes like volcanic eruptions.

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i hope you get it correct!! <3 can i plz get a brainlest!

Answer:

50 g

Explanation:

Please brainiest

Answer:

1) 7.80 X 10^22[tex]\frac{1}{6.02*10^{23} }[/tex] = .13

2) 5.6 [tex]\frac{6.02*10^{23} }{1}[/tex] = 3.4 X 10^24

3)3.81 [tex]\frac{1}{74.55}[/tex] X [tex]\frac{6.02*10^{23} }{1}[/tex] = 3.08 X 10^22

4) 399.91 [tex]\frac{4.05*10^{23} }{6.02*10^{23} }[/tex] = 269

5)4.32 [tex]\frac{1}{18.01}[/tex] X [tex]\frac{22.4}{1}[/tex] = 5.37

Explanation:

For 2 the correct answer is 3.4 instead of 3.2. The 3.4 is rounded from 3.37. Sadly I couldn't figure out the bonus.

Answer:

I think it would be Yellow

Answer:

14/2.1 thats just what i do

Explanation:

If the [OH⁻] of a solution is  2.7 × 10⁻⁴ mol/L the pOH of the solution is 3.569.

pH is used to measure whether the substance is acidic, basic or neutral and the range is 0-14.

To calculate the pOH it is expressed as:

pOH = - log[OH⁻]

        = - log[2.7 × 10⁻⁴]

        = - [log 2.7 + log  10⁻⁴]                        [log a × b = log + log b]

        = - [log 2.7 - 4 log 10]                          [log aˣ = x log a]

        = - [log 2.7 - 4 × 1]                                [log 10 = 1]

        = - [log 2.7 - 4]

        = - [0.431 - 4]

        = - [-3.569]

        = 3.569

Thus, from above conclusion we can say that If the [OH⁻] of a solution is  2.7 × 10⁻⁴ mol/L the pOH of the solution is 3.569.

Learn more about the pH here: https://brainly.com/question/24595796

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Answer:

is it a yes or no question

if it is yes

Explanation:

Answer:

it would need to lose energy

Explanation:

I don't really have an explanation

As the electrons gets closer to the nucleus, by the electrostatic force of attraction electrons are tightly bound to the nucleus. To move the inner electron to outer shell, high energy have to applied to weaken the nuclear force.

Nuclear force is the force by which the nucleon are bind in the nucleus and electrons are attracted towards the nucleus. The positively charged protons inside the nucleus electrostatically attracts the negatively charged electrons.

The minimum amount of energy required to remove an electron from the valence shell by overcoming the nuclear force is called ionization energy.

To bring an electron which is closer to the nucleus to the outer shell needs much energy to reduce the nuclear attractive pull. The energy need to gain.

Find more on ionization energy:

https://brainly.com/question/28385102

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Answer:

The pressure of the gas is 0.35 atm.

Explanation:

We can find the pressure of the gas by using the Ideal Gas Law:

[tex] P = \frac{nRT}{V} [/tex]

Where:

V: is the volume = 605 mL = 0.605 L

n: is the number of moles = 0.00803 moles

T: is the temperature = 39 °C = 312 K

R: is the gas constant = 0.082 L*atm/(K*mol)

Hence, the pressure is:

[tex] P = \frac{0.0083 moles*0.082 L*atm/(K*mol)*312 K}{0.605 L} = 0.35 atm [/tex]

Therefore, the pressure of the gas is 0.35 atm.

I hope it helps you!