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3 years ago

Melted wax has a temperature of 54 deg. Celsius. Physical or chemical property?

1 answer:

7 0

The melting of solid wax to form liquid wax and the evaporation of liquid wax to form wax vapor are physical changes. The burning of the wax vapor is a chemical change.

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(1) Write the net ionic equation for the reaction that occurs when equal volumes of 0.233 M aqueous acetylsalicylic acid (aspiri

AveGali [126]

Complete Question

The complete question is shown on the first uploaded image

Answer:

1) The ionic equation is

$HC_9H_7O_4 + (C_2 H_5)_3 N -----> C_9H_7O_4^- + (C_2 H_5)_3 NH^-$

At equilibrium The aniline will be favored

The pH of the solution is $pH = 7.12$

Explanation:

From the question we are told that

The concentration of aspirin is $C_A = 0.233M$

The acid dissociation constant for aspirin is $K_a = 3.0*10^{-4}$

The base dissociation constant for aniline is $K_b = 7.4 *10^{-10}$

The molecular formula for aspirin is $HC_9H_7O_4$

The molecular formula for aniline is $(C_2 H_5)_3 N$

So the net ionic reaction is

$HC_9H_7O_4 + (C_2 H_5)_3 N -----> C_9H_7O_4^- + (C_2 H_5)_3 NH^-$

Generally pKa is mathematically evaluated as

$pKa = -log(3.0*10^{-4})$

$= 3.52$

Generally pKb is mathematically represented as

$pKa = -log(7.4*10^{-10 })$

$= 9.13$

Generally

pKa + pKb = 14

So for the triethylammonium salt produced the pKa is

$pK_a__{s}} = 14 - 3.28$

$= 10.72$

As a result of the pKa of aspirin being lower that that of triethylammonium salt at equilibrium it implies that aniline would be favored

The pH of the solution is mathematically represented as

Since they are of equal mole

$pH = \frac{1}{2} (pKa + pKb + pKw)$

Where pKw is the pKw of water which has a value of 14

$pH = 0.5(14 + 3.52 + 3.28)$

$pH = 7.12$

5 0

3 years ago

Read 2 more answers

If a sample contains 100.0 g of lead atoms (Pb), how many atoms are present in the sample?

Igoryamba

Answer:

The answer to your question is the letter C. 2.906 x 10²³ atoms

Explanation:

Data

mass of Lead = 100 g

The Number of atoms = ?

Process

1.- Look for the atomic number of Lead in the periodic table

Atomic number = 207.2 g

2.- Use proportions and the Avogadro's number to calculate the number of atoms.

207.2 g ------------------ 6.023 x 10²³ atoms

100 g ----------------- x

x = (100 x 6.023 x 10²³) / 207.2

x = 6.025 x 10²⁵ / 207.2

x = 2.906 x 10²³ atoms

7 0

3 years ago

Read 2 more answers

Oak tree

Murljashka [212]

Oak tree, because it’s the primary producer

3 0

2 years ago

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Calculate the mass (in grams) of 0.473 mol of titanium

xz_007 [3.2K]

Explanation:

n=given mass ÷molar mass

make given mass become the subject of the formula by

multiplying the molar mass on both sides of the equation.

n=0.473mol

given mass=??

molar mass=48

therefore,given mass=n×molar mass

=0.473×48

=22.704grams

mass in grams is 22.704grams

7 0

3 years ago

Is calcium chloride soluble in water?

Alla [95]

Answer:

Yes

Explanation:

Calcium Chloride is an inorganic compound, a salt that can dissolve in water.

5 0

3 years ago

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