A sample of silver metal contains 1.91 X 1021 atoms. How many moles of silver is<br> this?

What mass of Fe(OH)3 is produced when 35 mL of 0.250 M Fe(NO3)3 solution is mixed with 55 mL of a 0.180 M

Zina [86]

Answer:

0.35 g.

Explanation:

We'll begin by calculating the number of mole of Fe(NO3)3 in 35 mL of 0.250 M Fe(NO3)3 solution.

This is illustrated below:

Molarity of Fe(NO3)3 = 0.250 M

Volume = 35 mL = 35/1000 = 0.035 L

Mole of Fe(NO3)3 =?

Molarity = mole /Volume

0.250 = mole of Fe(NO3)3 / 0.035

Cross multiply

Mole of Fe(NO3)3 = 0.25 x 0.035

Mole of Fe(NO3)3 = 8.75×10¯³ mole

Next, we shall determine the number of mole of KOH in 55 mL of 0.180 M

KOH solution. This is illustrated below:

Molarity of KOH = 0.180 M

Volume = 55 mL = 55/1000 = 0.055 L

Mole of KOH =.?

Molarity = mole /Volume

0.180 = mole of KOH /0.055

Cross multiply

Mole of KOH = 0.180 x 0.055

Mole of KOH = 9.9×10¯³ mole.

Next, we shall write the balanced equation for the reaction. This is given below:

3KOH + Fe(NO3)3 —> Fe(OH)3 + 3KNO3

From the balanced equation above,

3 moles of KOH reacted with 1 mole of Fe(NO3)3 to produce 1 mole of Fe(OH)3.

Next, we shall determine the limiting reactant. This can be obtained as follow:

From the balanced equation above,

3 moles of KOH reacted with 1 mole of Fe(NO3)3.

Therefore, 9.9×10¯³ mole of KOH will react with = (9.9×10¯³ x 1)/3 = 3.3×10¯³ mole of Fe(NO3)3.

From the above illustration, we can see that only 3.3×10¯³ mole out of 8.75×10¯³ mole of Fe(NO3)3 given is needed to react completely with 9.9×10¯³ mole of KOH.

Therefore, KOH is the limiting reactant and Fe(NO3)3 is the excess reactant.

Next, we shall determine the number of mole of Fe(OH)3 produced from the reaction.

In this case, we shall use the limiting reactant because it will give the maximum yield of Fe(OH)3 as all of it is consumed in the reaction.

The limiting reactant is KOH and the mole of Fe(OH)3 produce can be obtained as follow:

From the balanced equation above,

3 moles of KOH reacted to produce 1 mole of Fe(OH)3.

Therefore, 9.9×10¯³ mole of KOH will react to produce = (9.9×10¯³ x 1)/3 = 3.3×10¯³ mole of Fe(OH)3.

Finally, we shall convert 3.3×10¯³ mole of Fe(OH)3 to grams. This can be obtained as follow:

Molar mass of Fe(OH)3 = 56 + 3(16 + 1) = 56 + 3(17) = 107 g/mol

Mole of Fe(OH)3 = 3.3×10¯³ mole

Mass of Fe(OH)3 =?

Mole = mass /Molar mass

3.3×10¯³ = Mass of Fe(OH)3 / 107

Cross multiply

Mass of Fe(OH)3 = 3.3×10¯³ x 107

Mass of Fe(OH)3 = 0.3531 ≈ 0.35 g.

Therefore, 0.35 g of Fe(OH)3 was produced from the reaction.

8 0

3 years ago

What elegant has 2 valence electrons

scZoUnD [109]

Explanation:

Calcium is the element that has 2 valence electrons.

8 0

3 years ago

Propiedades químicas del óxido

tangare [24]

Óxidos básicos: Son formados por metales. El metal presente en su fórmula puede presentar carga eléctrica +1 y +2, o sea, poseer carácter iónico. Ejemplos: Na2O (óxido de sodio), BaO (óxido de bario).

Óxidos neutros: Son compuestos por no metales. No reaccionan con agua, ácido o base, en razón del enlace covalente que une sus componentes; de ahí el por qué de ser llamados óxidos inertes. Ejemplos: monóxido de dinitrógeno (N2O) y monóxido de carbono (CO).

Óxidos ácidos: También conocidos como anhídridos de ácidos, son formados por no metales y presentan carácter covalente. En la presencia de agua, producen ácidos y en la presencia de bases, origina sal y agua. Ejemplo: CO2 (dióxido de carbono o gas carbono) y el SO2 (dióxido de azufre)

Óxidos dobles o mixtos: La combinación de dos óxidos de un mismo elemento, da origen a este tipo de óxidos. Ejemplo: magnetita (Fe2O4), unión de los óxidos de hierro (Fe) y oxígeno (O).

Óxidos anfóteros: Presentan ambigüedad, en la presencia de un ácido se comportan como óxidos básicos y en la presencia de una base, como óxidos ácidos. Ejemplos: óxido de aluminio (Al2O3 ) y el óxido de zinc (ZnO).

Peróxidos: Compuestos que poseen en su fórmula el grupo (O2)2- . Los peróxidos más comunes son formados por hidrógeno, metales alcalinos y metales alcalinos térreos. Ejemplos: agua oxigenada (H2O) y peróxido de sodio (Na2O2).

8 0

3 years ago

THIS IS A THREE PART QUESTION IF YOU CAN HELP IT WOULD BE REALLY APPRECIATED SO I DONT FAIL.

Nostrana [21]

Answer:

1. B = 1.13M

2. A. 8.46%

3. D = 0.0199

Explanation:

1. Molarity of a a solution = number of moles of solute/ volume of solution in L

Number of moles of solute = mass of solute/molar mass of solute

Molar mass of NaC₂H₃O₂ = 82 g/mol, mass of NaC₂H₃O₂ = 245 g

Number of moles of NaC₂H₃O₂ = 245 g / 82 g/mol = 2.988 moles

Molarity of solution = 2.988 mols/ 2.65 L = 1.13 M

2. Percentage by mass of a substance = mass of substance /mass of solution × 100%

Mass of 2.65 L of water = density × volume

Density of water = 1 Kg/L = 1000 g/L; volume of waterb= 2.65 L

Mass of water = 1000 g/L × 2.65 L = 2650 g

Mass of solution = mass of water + mass of solute = 245 + 2650 =2895 g

Percentage by mass of NaC₂H₃O₂ = 245/2895 × 100% = 8.46%

3. Mole fraction of NaC₂H₃O₂ = moles of NaC₂H₃O₂/moles of solution

Moles of water = mass /molar mass

Mass of water = 2650 g; molar mass of water = 18 g/mol

Moles of water = 2650 g / 18 g/mol = 147.222 moles

Moles of solution = moles of solute + moles of water = 147.222 + 2.988 = 150.21

Moles of NaC₂H₃O₂ =2.988 moles

Moles fraction of NaC₂H₃O₂ =2.988/150.21 = 0.0199

6 0

3 years ago

After careful analysis, an electromagnetic wave is found to have a frequency of 7.8 x 10^6 Hz. What is the speed of the wave?

damaskus [11]

Answer:

Explanation:

4 0

3 years ago

A sample of silver metal contains 1.91 X 1021 atoms. How many moles of silver is this?