How many different elements are involved in the reaction shown below?

Pyridine, C5H5N, is a polar organic solvent. How many carbon atoms are in 7.05 moles of pyridine? 4.24 x 1024 4.24 x 10, 24 2.12

leonid [27]

Answer:

2.122×10^25atoms

Explanation:

number of moles=mass/molar mass

7.05moles= mass of pyridine/79

reacting mass of pyridine=556.95

C5H5N= (12×5)+(5)+(14)=79

C5=60

to find the mass of carbon in 556.95g of pyridine we take the stoichometric ratio

60[C5] -----> 79[C5H5N]

x[C5] --------> 556.95g[C5H5N]

cross multiply

x=(60×556.95)/79

x=423g of carbon

moles=mass/molar mass

moles of carbon=423/12

moles=35.25moles of carbon

moles=number of particles/Avogadro's constant

35.25=number of particles/6.02×10^23

number of particles=2.122×10^25atoms of carbon

3 0

2 years ago

Aspirin (acetylsalicylic acid, C9H8O4) is a weak monoprotic acid. To determine its acid-dissociation constant, a student dissolv

Triss [41]

Answer:

1. $3.57\times 10^{-4}$ was the $K_a$ value calculated by the student.

2. $5.93\times 10^{-4}$ was the $K_b$ of ethylamine value calculated by the student.

Explanation:

1.

The $pH$ value of Aspirin solution = 2.62

$pH=-\log[H^+]$

$[H^+]=10^{-2.62}=0.00240 M$

Moles of s asprin = $\frac{2.00 g}{180 g/mol}=0.01111 mol$

Volume of the solution = 0.600 L

The initial concentration of Aspirin = c = $\frac{0.01111 mol}{0.600 L}=0.0185 M$

$HAs\rightleftharpoons As^-+H^+$

initially

c 0 0

At equilibrium

(c-x) x x

The expression of dissociation constant :

$K_a=\frac{[As^-][H^+]}{[HAs]}$ :

$K_a=\frac{x\times x }{(c-x)}$

$=\frac{0.00240 M\times 0.00240 M}{(0.0185-0.00240 )}$

$K_a=3.57\times 10^{-4}$

$3.57\times 10^{-4}$ was the $K_a$ value calculated by the student.

2.

The $pH$ value of ethylamine = 11.87

$pH+pOH=14$

$pOH=14-11.87=2.13$

$pOH=-\log[OH^-]$

$[OH^-]=10^{-2.13}=0.00741 M$

The initial concentration of ethylamine = c = 0.100 M

$C_2H_5NH_2+H_2O\rightleftharpoons C_2H_5NH_3^{+}+OH^-$

initially

c 0 0

At equilibrium

(c-x) x x

The expression of dissociation constant :

$K_b=\frac{[C_2H_5NH_3^{+}][OH^-]}{[C_2H_5NH_2]}$ :

$K_b=\frac{x\times x}{(c-x)}$

$=\frac{0.00741\times 0.00741}{(0.100-0.00741)}$

$K_b=5.93\times 10^{-4}$

$5.93\times 10^{-4}$ was the $K_b$ of ethylamine value calculated by the student.

3 0

3 years ago

What is the mass in grams of 3x10 atoms of helium

Zepler [3.9K]

Answer:

here

Explanation:

What is the total mass of $$3.01 x 10^23$$ atoms of helium gas?

✓ Well $$"Avogadro's number"$$ of helium atoms has a mass of $$4.0*g$$. Explanation: And $$"Avogadro's number"$$

3 0

2 years ago

How are mass and weight alike?

joja [24]

Both mass and weight are measured by using scales.

7 0

2 years ago

If a 8 N force acts on a 4kg object, what is the resulting acceleration

cluponka [151]

The answer is 2 because you have to divide these numbers.<span />

7 0

3 years ago