Complex conversion between units may require using conversion factor

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 $C_4H_8O_4$

8 0

3 years ago

The rate constant for this second‑order reaction is 0.610 M − 1 ⋅ s − 1 0.610 M−1⋅s−1 at 300 ∘ C. 300 ∘C. A ⟶ products A⟶product

Darya [45]

Answer: It takes 3.120 seconds for the concentration of A to decrease from 0.860 M to 0.260 M.

Explanation:

Integrated rate law for second order kinetics is given by:

$\frac{1}{a}=kt+\frac{1}{a_0}$

k = rate constant = $0.610M^{-1}s^{-1}$

$a_0$ = initial concentration = 0.860 M

a= concentration left after time t = 0.260 M

$\frac{1}{0.260}=0.860\times t+\frac{1}{0.860}$

$t=3.120s$

Thus it takes 3.120 seconds for the concentration of A to decrease from 0.860 M to 0.260 M.

8 0

4 years ago

Add a nail in CuSO4 Sodium, the colour of CuSO4 disappears why?

Gre4nikov [31]

The iron nail displaces the Cu from the copper sulfate solution. This results in the color of CuSO4's disappearance. Copper is less reactive than iron.

5 0

4 years ago

Read 2 more answers

How many moles of co2 are produced when 5.70 mol of ethane are burned in an excess of oxygen

sweet-ann [11.9K]

I believe the answer is 6

4 0

3 years ago

8. What is the oxidation number of N in KNO3?

Elza [17]

Answer:

The oxidation state of N in the KNO3 is +5

Explanation:

Oxidation rules:

1. Oxygen is -2, unless in peroxides.

2. Group 1 metals = +1

3. Group 2 metals = +2

4. If the molecule is neutral, all of the oxidation numbers have to add up to zero.

5. If the molecule is charged, all of the oxidation numbers have to add up to the charge of the molecule.

So, the given formula represents the salt compound formula unit of potassium nitrate: KNO3

The formula unit is uncharged.

From our rules, we know that,

O = -2

And we can find K on the periodic table, in the first group, thus giving it a +1 charge. Now let's put it all together.

K = +1

N = x

O = -2

Let's take into account the number of atoms of each element we have and make an equation since we know everything has to add up to zero since the molecules are neutral.

+1 +x+3 (-2) = 0 (notice we multiplied 3 by -2 because in the formula we have 3 atoms of oxygen with -2 charge each)

x - 5 = 0

x = 5

Therefore, the oxidation number of N in KNO3 is +5.

5 0

3 years ago