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3 years ago

7

Calculate molality of a 2m aq solution of sodium chloride with density 1.35g/mol

1 answer:

swat323 years ago

5 0

There are a number of ways to express concentration of a solution. This includes molarity and molality. Molarity is expressed as the number of moles of solute per volume of the solution while molality is expressed as the number of moles solute per mass of solution. Calculation is as follows:

(2 mol NaCl / L solution) ( 1 cm^3 / 1.35 g) ( 1000 L / 1 cm^3) (1000 g /kg) = 1.5 x 10^6 mol / kg solution

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Air is an example of a mixture because the elements and compounds that make up air retain their individual properties. True Fals

Helga [31]

i believe its true bc ik for sure air is a homogenous mixture

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3 years ago

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Explain the units and how to solve the following metric conversion then solve the metric conversion by filling in the blank 12KM

LiRa [457]

Answer:- 12 km = 12000 m

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In metric conversions, kilo means 1000.

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$12km(\frac{1000m}{1km})$

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3 years ago

The elemental analysis of an organic solid extracted from gum arabic (a gummy substance used in adhesives, inks, and pharmaceuti

Evgesh-ka [11]

Answer:

The molar mass of the organic solid is 120.16 g/mol.

The molecular formula of an organic solid is $C_4H_8O_4$

Explanation:

Let the molecular mass of an organic solid be $C_xH_yO_z$

$\Delta T_b=K_b\times m$

$Delta T_b=K_b\times \frac{\text{Mass of solid}}{\text{Molar mass of solid}\times \text{Mass of diphenyl in Kg}}$

where,

$\Delta T_f$ =Elevation in boiling point = $=1.5^oC$

Mass of organic solid= 0.561 g

Mass of diphenyl = 24.9 g = 0.0249 kg (1 kg = 1000 g)

$K_b$ = boiling point constant = 8.00 °C/m

m = molality

Now put all the given values in this formula, we get

$1.5^oC=8.00 ^oC/m\times \frac{0.561 g}{\text{Molar mass of solid}\times 0.0249 kg}$

${\text{Molar mass of solid}}=120.16 g/mol$

$\%=\frac{\text{Number of atoms}\times \text{mass of an atom}}{\text{molas mass of compound}}\times 100$

Percentage of carbon in an organic solid = 40.0%

$40\%=\frac{x\times 12 g/mol}{120.16 g/mol}\times 100$

x = 4.0

Percentage of hydrogen in an organic solid = 6.7%

$6.7\%=\frac{y\times 1 g/mol}{120.16 g/mol}\times 100$

y = 8.0

Percentage of hydrogen in an organic solid = 6.7%

$53.3\%=\frac{x\times 12 g/mol}{120.16 g/mol}\times 100$

y = 4.0

The molecular formula of an organic solid is $C_4H_8O_4$

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3 years ago

What is usually needed to help a decomposition reaction occur

ArbitrLikvidat [17]

<u>The addtion of energy</u> <span>is usually needed to help a decomposition reaction occur</span>

3 0

2 years ago

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Consider the unbalanced chemical equation HBr + B = BBr3 + H2. When

Vitek1552 [10]

Answer:

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Explanation:

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3 years ago