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3 years ago

I need help with 13. What do I do with the parentheses?

Chemistry

1 answer:

wel3 years ago

5 0

With the parentheses you just multiple what’s inside them times what’s on the outside so for P it’s 1 x 2 = 2 and for O it’s 4 x 2 = 8.

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Use the ideal gas law to calculate the concentrations of nitrogen and oxygen present in air at a pressure of 1.0 atm and a tempe

notka56 [123]

Answer:

[N₂] = 0.032 M

[O₂] = 0.0086 M

Explanation:

Ideal Gas Law → P . V = n . R . T

We assume that the mixture of air occupies a volume of 1 L

78% N₂ → Mole fraction of N₂ = 0.78

21% O₂ → Mole fraction of O₂ = 0.21

1% another gases → Mole fraction of another gases = 0.01

In a mixture, the total pressure of the system refers to total moles of the mixture

1 atm . 1L = n . 0.082L.atm/mol.K . 298K

n = 1 L.atm / 0.082L.atm/mol.K . 298K → 0.0409 moles

We apply the mole fraction to determine the moles

N₂ moles / Total moles = 0.78 → 0.78 . 0.0409 mol = 0.032 moles N₂

O₂ moles / Total moles = 0.21 → 0.21 . 0.0409 mol = 0.0086 moles O₂

4 0

4 years ago

Calculate the vapor pressure in torr of a solution containng 24.5 g of glycerin (C3H8O3) in 135 mL water at 30.0* C; the vapor p

Otrada [13]

Psolution = X · PH_20
= 0.966 · 31.8 torr
= 30.7 torr

3 0

3 years ago

How many grams of solid NaOH are required to prepare a 400ml of a 5N solution? show your work!

Nuetrik [128]

<u>Answer:</u> The mass of solid NaOH required is 80 g

<u>Explanation:</u>

Equivalent weight is calculated by dividing the molecular weight by n factor. The equation used is:

$\text{Equivalent weight}=\frac{\text{Molecular weight}}{n}$

where,

n = acidity for bases = 1 (For NaOH)

Molar mass of NaOH = 40 g/mol

Putting values in above equation, we get:

$\text{Equivalent weight}=\frac{40g/mol}{1eq/mol}=40g/eq$

Normality is defined as the umber of gram equivalents dissolved per liter of the solution.

Mathematically,

$\text{Normality of solution}=\frac{\text{Number of gram equivalents} \times 1000}{\text{Volume of solution (in mL)}}$

Or,

$\text{Normality of solution}=\frac{\text{Given mass}\times 1000}{\text{Equivalent mass}\times \text{Volume of solution (in mL)}}$ ......(1)

We are given:

Given mass of NaOH = ?

Equivalent mass of NaOH = 40 g/eq

Volume of solution = 400 mL

Normality of solution = 5 eq/L

Putting values in equation 1, we get:

$5eq/L=\frac{\text{Mass of NaOH}\times 1000}{40g/eq\times 400mL}\\\\\text{Mass of NaOH}=80g$

Hence, the mass of solid NaOH required is 80 g

4 0

4 years ago

Which list of elements consists of metalloids, only?

rewona [7]

Answer: D

Explanation: Boron (B), Silicon (Si), Germanium (Ge), Arsenic (As), Antimony (Sb), Tellurium (Te) and, Astatine (At) are all metalloids

4 0

3 years ago

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The valance number of M is 3 . what is the formula of its phosphorus

lakkis [162]

The formula for phosphorus is P4

3 0

3 years ago