All categories

3 years ago

How many atoms are in 6.3 moles of lead

Chemistry

1 answer:

densk [106]3 years ago

4 0

Answer:

3.79 x 10²⁴atoms

Explanation:

Given parameters:

Number moles of lead = 6.3moles

Unknown:

Number of atoms = ?

Solution:

To solve this problem,

1 mole of a substance contains 6.02 x 10²³ atoms

6.3 mole of Pb will contain 6.3 x 6.02 x 10²³ = 3.79 x 10²⁴atoms

You might be interested in

When the equation Sn + HNO₃ → SnO₂ + NO₂ + H₂O is balanced in acidic solution, what is the smallest whole-number coefficient for

balu736 [363]

Answer:

Explanation:

Hello,

In this case, for the given reaction we first assign the oxidation state for each species:

$Sn^0 + H^+N^{5+}O^{-2}_3 \rightarrow Sn^{4+}O_2 + N^{4+}O^{2-}_2 + H^+_2O^-$

Whereas the half reactions are:

$Sn^0+2H_2O \rightarrow Sn^{4+}O_2 +4H^++4e^-\\\\H^++H^+N^{5+}O^{-2}_3 +1e^-\rightarrow N^{4+}O^{2-}_2+H_2O$

Next, we exchange the transferred electrons:

$1\times(Sn^0+2H_2O \rightarrow Sn^{4+}O_2 +4H^++4e^-)\\\\4\times (H^++H^+N^{5+}O^{-2}_3 +1e^-\rightarrow N^{4+}O^{2-}_2+H_2O)\\\\\\Sn^0+2H_2O \rightarrow Sn^{4+}O_2 +4H^++4e^-\\\\4H^++4H^+N^{5+}O^{-2}_3 +4e^-\rightarrow 4N^{4+}O^{2-}_2+4H_2O$

Afterwards, we add them to obtain:

$Sn^0+2H_2O+4H^++4H^+N^{5+}O^{-2}_3 \rightarrow Sn^{4+}O_2 +4H^++4N^{4+}O^{2-}_2+4H_2O$

By adding and subtracting common terms we obtain:

$Sn^0+4H^+N^{5+}O^{-2}_3 \rightarrow Sn^{4+}O_2 +4N^{4+}O^{2-}_2+2H_2O$

Finally, by removing the oxidation states we have:

$Sn + 4HNO_3 \rightarrow SnO_2 + 4NO_2 + 2H_2O$

Therefore, the smallest whole-number coefficient for Sn is 1.

Regards.

6 0

3 years ago

. What is the mass, in grams, of a sample of 7.83 × 1024 atoms of helium (He)?

erica [24]

Moles He = 7.83 x 10^24 / 6.02 x 10^23 =13.0

mass He = 13.0 mol x 4.00 g/mol = 52.0 g

6 0

3 years ago

What is the pH of 0.10 M NaF(aq). The Ka of HF is 6.8 x 10-4

dsp73

Given information:

Concentration of NaF = 0.10 M

Ka of HF = 6.8*10⁻⁴

To determine:

pH of 0.1 M NaF

Explanation:

NaF (aq) ↔ Na+ (aq) + F-(aq)

[Na+] = [F-] = 0.10 M

F- will then react with water in the solution as follows:

F- + H2O ↔ HF + OH-

Kb = [OH-][HF]/[F-]

Kw/Ka = [OH-][HF]/[F-]

At equilibrium: [OH-]=[HF] = x and [F-] = 0.1 - x

10⁻¹⁴/6.8*10⁻⁴ = x²/0.1-x

x = [OH-] = 1.21*10⁻⁶ M

pOH = -log[OH-] = -log[1.21*10⁻⁶] = 5.92

pH = 14 - pOH = 14-5.92 = 8.08

Ans: (b)

pH of 0.10 M NaF is 8.08

6 0

3 years ago

¿Cómo se escribe la fórmula molecular (orden de los iones)?

cluponka [151]

Answer:

A la izquierda el catión y a la derecha el anión.

Explanation:

¡Hola!

En este caso, y basado en las normas IUPAC para la escritura de las fórmulas moleculares, es necesario primero escribir el catión a la izquerda, seguido del anión a la derecha, tal y como se muestra en los siguientes ejemplos, recordando que el catión es el ion cargado positivamente y el anión, negativamente:

$K^+Cl^-\\\\Ag_2^+(SO_4)^{2-}$

Los cuales son cloruro de potasio y sulfato de plata respectivamente. También es necesario tener en cuenta que los metales tienden a ser cationes por su capacidad de perder electrones, mientras que los no metales a ganarlos y por ende resultar como aniones.

¡Un gusto ayudarte!

6 0

3 years ago

Whats the difference between Homogeneous and Hetrogeneuos?

irakobra [83]

Answer:

Homogeneous - With a uniform appearance

Heterogeneous - With visible differences in the mixture

Explanation:

Referring to mixtures, homogeneous looks the same throughout, while heterogeneous has particles or whatnot.

Basically:

Homo means same

Hetero means different

6 0

3 years ago