A gas mixture contains 1.61 moles of hydrogen and 2.31 moles of oxygen. What is the mole fraction of oxygen?

Chromosomes move to the middle of the cell during what phase

Alexxandr [17]

The Anaphase stage

Happy studying!

6 0

4 years ago

Do you think migration is a pattern of behavior? Explain.

ohaa [14]

Yes, because people tend to move toward better weather and climate. People follow food, and people follow jobs.

3 0

3 years ago

Calculate the weight of solid NaOH required to prepare (a) 5 liters of a 2 M solution, (b) 2 liters of a solution of pH 11.5?

aalyn [17]

Answer:

A. 400g of NaOH.

B. 0.253g of NaOH.

Explanation:

A. The following data were obtained from the question:

Volume = 5 L

Molarity = 2 M

Mass =..?

Next, we shall determine the number of mole of NaOH. This can be obtain as follow:

Molarity = mole /Volume

2 = mole/5

Cross multiply

Mole = 2 x 5

Mole of NaOH = 10 moles

Finally, we shall convert 10 moles of NaOH to grams. This is illustrated below:

Mole of NaOH = 10 moles

Molar mass of NaOH = 23 + 16 + 1 = 40g/mol

Mass of NaOH =?

Mole = mass /molar mass

10 = mass of NaOH /40

Cross multiply

Mass of NaOH = 10 x 40

Mass of NaOH = 400g

Therefore, 400g of NaOH is needed to prepare the solution.

B. The following data were obtained from the question:

pH = 11.5

Volume = 2 L

Next, we shall determine the pOH of the solution. This can be obtain as shown below:

pH + pOH = 14

pH = 11.5

11.5 + pOH = 14

Collect like terms

pOH = 14 – 11.5

pOH = 2.5

Next, we shall determine the concentration of the hydroxide ion, [OH-] in the solution.

This is illustrated below:

pOH = - Log [OH-]

pOH = 2.5

2.5 = - Log [OH-]

-2.5 = Log [OH-]

Take the antilog of both side

[OH-] = antilog (-2.5)

[OH-] = 3.16×10¯³ M

Next, we shall determine the concentration of NaOH. This is illustrated below:

NaOH —> Na+ + OH-

From the balanced equation above,

1 mole of NaOH produced 1 mole of OH-.

Therefore, 3.16×10¯³ M NaOH will also produce 3.16×10¯³ M OH-.

Therefore, the concentration of NaOH is 3.16×10¯³ M

Next, we shall determine the number of mole of NaOH in the solution. This can be obtain as follow:

Molarity = 3.16×10¯³ M

Volume = 2 L

Mole of NaOH =?

Molarity = mole /Volume

3.16×10¯³ = mole of NaOH / 2

Cross multiply

Mole of NaOH = 3.16×10¯³ x 2

Mole of NaOH = 6.32×10¯³ mole

Finally, we shall convert 6.32×10¯³ mole of NaOH to grams

Mole of NaOH = 6.32×10¯³ mole

Molar mass of NaOH = 23 + 16 + 1 = 40g/mol

Mass of NaOH =?

Mole = mass /molar mass

6.32×10¯³ = mass of NaOH /40

Cross multiply

Mass of NaOH = 6.32×10¯³ x 40

Mass of NaOH =0.253 g

Therefore, 0.253g of NaOH is needed to prepare the solution.

8 0

3 years ago

Alborosie

Charge:

An electron has a negative charge and a neutron has a neutral charge.

Size:

Electrons have a really small mass whereas the neutron has a mass of about 1 amu.

Location:

Neutrons are found in center of an atom, but electrons are around it.

Number:

The number of electrons and neutrons in atom varies.

7 0

3 years ago

What are some chemical formulas for compounds?

Galina-37 [17]

Hello there!

First, we need to know what compounds are.
Compounds "are pure substances that are made up of two or more elements that are chemically combined in fixed mass ratios."

Now we need to understand what chemical formulas are.
The compounds have a chemical formula which tell us that
a) the elements that are present in the compound
b) the ratio of these elements in the compound

What are some chemical formulas for compounds?
Well, we start with water. The chemical formula for water is H2O

When we go back to the definition of compounds, it says it is when a pure substance that are made up two or more elements. So, whatever is a pure substance and it's made up of two elements. These elements are Hydrogen and Oxygen. And keep an mind that water is made up with metal plus non-metal.

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Here are one more chemical formulas for compounds
Sodium Chloride = NaCI

I included a picture that might help you too. (Credit to google image)

4 0

3 years ago