For each relationship, write 2 conversion factors:

PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEWSE HELP PLEASE H

marishachu [46]

Answer:

23.6 moles

Explanation:

From the question given above, the following data were obtained:

Mass of air = 3.6 Kg

Mass percentage of O₂ = 21%

Number of mole of O₂ =?

Next, we shall convert 3.6 Kg of air to grams (g). This can be obtained as follow:

1 kg = 1000 g

Therefore,

3.6 Kg = 3.6 Kg × 1000 / 1 kg

3.6 Kg = 3600 g

Next, we shall determine the mass of O₂ in the air. This can be obtained as follow:

Mass of air = 3600 g

Mass percentage of O₂ = 21%

Mass of O₂ =?

Mass of O₂ = 21% × 3600

Mass of O₂ = 21/100 × 3600

Mass of O₂ = 756 g

Finally, we shall determine the number of mole of O₂ in the sample of air. This can be obtained as follow:

Mass of O₂ = 756 g

Molar mass of O₂ = 2 × 16 = 32 g/mol

Number of mole of O₂ =?

Mole = mass /Molar mass

Number of mole of O₂ = 756 / 32

Number of mole of O₂ = 23.6 moles

Thus, the number of mole of O₂ in the

sample of air is 23.6 moles

7 0

2 years ago

How many ions are present in 75.0g of magnesium sulfate

Ostrovityanka [42]

Answer:

7.5×10²³ ions

Explanation:

Given data:

Mass of magnesium sulfate = 75.0 g

Number of ions = ?

Solution:

Number of moles of magnesium sulfate:

Number of moles = mass/molar mass

Number of moles = 75.0 g/ 120.36 g/mol

Number of moles = 0.623 mol

Magnesium sulfate formula: MgSO₄

Number of moles of ions in 1 mole of MgSO₄ = 2 mol (Mg²⁺ and SO₄²⁻)

Number of moles of ion in 0.623 moles of MgSO₄:

2 mole ×0.623 = 1.246 mol

Number of ions:

1 mole contain 6.022×10²³ ions

1.246 mol × 6.022×10²³ ions / 1mol

7.5×10²³ ions

4 0

3 years ago

in the two stage cooling method what is the maximum amount of time allowed for both stages cooling food from 135 to 41 degrees F

BlackZzzverrR [31]

In the past, restaurants had four hours, straight through, to cool food to 41°F or lower. Now the FDA recommends cooling food in two stages -- from 135°F to 70°F in two hours then from 70°F to 41°F or lower in an additional four hours for a total cooling time of six hours
Explanation:
the two-stage cooling method is a Food Code counselled procedure for cooling food in restaurants and foodservice institutions. within the two-stage cooling methodology, food is cooled from 140° F (60° C) to 70° F (21° C) among 2 hours and to 41° F (5° C) or lower among four hours. Use of this cooling methodology ensures that food is cooled quickly and safely and has no harmful effects.

3 0

3 years ago

Read 2 more answers

Which of the following combination of elements would result in covalent compound? * W X Y Z Vand X Wand Z Y and Z Wand y

TEA [102]

Answer:

C. Y & Z

Explanation:

V, W are imaginary metals here because their valence electrons are typically less than 4. X, Y, Z are non-metals and have higher valence electrons. Here, if V or W bind with X, Y, or Z we make ionic bond (because metal + non metal = ionic). But, if X binds with Y or Z or any combinations of any two of the three non-metals results in covalent bond (non metal + non metal = covalent).

Thus, Y and Z make covalent.

4 0

2 years ago

A certain radioactive element has a half-life of one hour. If you start with 40.0 grams of the element at noon, how much of the

Tpy6a [65]

If you start with 40.0 grams of the element at noon, 10.0 grams radioactive element will be left at 2 p.m. The correct answer between all the choices given is the second choice or letter B. I am hoping that this answer has satisfied your query and it will be able to help you in your endeavor, and if you would like, feel free to ask another question.

5 0

3 years ago

Read 2 more answers