Which activity requires people to use fossil-fuel resources?

Suppose of potassium sulfate is dissolved in of a aqueous solution of sodium chromate. Calculate the final molarity of potassium

dimulka [17.4K]

Answer:

This question is incomplete, here's the complete question:

"Suppose 0.0842g of potassium sulfate is dissolved in 50.mL of a 52.0mM aqueous solution of sodium chromate. Calculate the final molarity of potassium cation in the solution. You can assume the volume of the solution doesn't change when the potassium sulfate is dissolved in it. Round your answer to 2 significant digits."

Explanation:

Reaction :-

K2SO4 + Na2CrO4 ------> K2CrO4 + Na2SO4

Mass of K2SO4 = 0.0842 g, Molar mass of K2SO4 = 174.26 g/mol

Number of moles of K2SO4 = 0.0842 g / 174.26 g/mol = 0.000483 mol

Concentration of Na2CrO4 = 52.0 mM = 52.0 * 10^-3 M = 0.052 mol/L

Volume of Na2CrO4 solution = 50.0 ml = 50 L / 1000 = 0.05 L

Number of moles of Na2CrO4 = 0.05 L * 0.052 mol/L = 0.0026 mol

Since number of moles of K2SO4 is smaller than number of moles Na2CrO4, so 0.000483 mol of K2SO4 will react with 0.000483 mol of Na2CrO4 will produce 0.000483 mol of K2CrO4.

0.000483 mol of K2CrO4 will dissociate into 2* 0.000483 mol of K^+

Final concentration of potassium cation

= (2*0.000483 mol) / 0.05 L = 0.02 mol/L = 0.02 M

8 0

3 years ago

As the temperature of a liquid increases, its viscosity _____. increases stays the same decreases

Valentin [98]

As the temperature of a liquid increases, its viscosity decreases.

5 0

2 years ago

Read 2 more answers

What is the energy of a photon with: a wavelength of 827 nm? What type of radiation is it?

xeze [42]

Explanation:

Given parameters:

Wavelength of photon = 827nm = 827 x 10⁻⁹m

Unknown:

Energy of the photon = ?

Type of radiation = ?

Solution:

The energy of a photon can be derived using the expression below:

E = $\frac{h c}{wavelength}$

h is the Planck's constant = 6.63 x 10⁻³⁴m²kg/s

c is the speed of light = 3 x 10⁸m/s

Insert the parameters and solve;

E = $\frac{6.63 x 10^{-34} x 3 x 10^{8} }{827x 10^{-9} }$

E = 2.4 x 10⁻¹⁹J

Type of radiation:

Near infrared radiation

7 0

2 years ago

Ammonia NH3 percentage composition

Firlakuza [10]

Answer:

82.24% percent composition of N and 17.76% percent composition of H .

Explanation:

3 0

3 years ago

Mole-Atom Conversions

iragen [17]

Answer:

Explanation:

1) How many moles are 1.55 × 10²⁷ atoms of zinc?

Answer:

0.26 × 10⁴ mole

Explanation:

The given problem will solve by using Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.

The number 6.022 × 10²³ is called Avogadro number.

For example,

18 g of water = 1 mole = 6.022 × 10²³ molecules of water

1.008 g of hydrogen = 1 mole = 6.022 × 10²³ atoms of hydrogen

For 1.55 × 10²⁷ atoms of zinc:

1.55 × 10²⁷ atoms × 1 mole/ 6.022 × 10²³ atoms

0.26 × 10⁴ mole

2) How many atoms are in 25.0 moles of calcium?

Answer:

150.55 × 10²³ atoms.

Explanation:

According to Avogadro number,

one mole of substance = 6.022 × 10²³ atoms

The number 6.022 × 10²³ is called Avogadro number.

For 25.0 moles of calcium:

one mole of calcium = 6.022 × 10²³ atoms

25.0 mole × 6.022 × 10²³ atoms /1 mole

150.55 × 10²³ atoms.

So 25.0 moles of calcium contain 150.55 × 10²³ atoms.

3) = How many atoms are in 0.35 moles of carbon?

Answer:

2.12× 10²³ atoms.

Explanation:

According to Avogadro number,

one mole of substance = 6.022 × 10²³ atoms

The number 6.022 × 10²³ is called Avogadro number.

For 0.35 moles of carbon:

one mole of carbon = 6.022 × 10²³ atoms

0.35 mole × 6.022 × 10²³ atoms /1 mole

2.12× 10²³ atoms.

So 0.35 moles of carbon contain 2.12× 10²³ atoms.

4 ) How many moles are 7.6 × 10²⁴ atoms of hellium?

The given problem will solve by using Avogadro number.

It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.

The number 6.022 × 10²³ is called Avogadro number.

For example,

18 g of water = 1 mole = 6.022 × 10²³ molecules of water

1.008 g of hydrogen = 1 mole = 6.022 × 10²³ atoms of hydrogen

For 7.6 × 10²⁴ atoms of hellium:

7.6 × 10²⁴ atoms × 1 mole/ 6.022 × 10²³ atoms

12. 6 mole

Mass - Mole conversion:

How many moles in 28.0 gram of oxygen?

Answer:

1.75 mol

Explanation:

Given data:

Mass of oxygen = 28 g

Number of moles = ?

Solution:

Formula:

Number of moles = mass/ molar mass

Molar mass of oxygen = 16 g/mol

Now we will put the values in formula:

Number of moles = 28 g / 16 g/mol

Number of moles = 1.75 mol

So 28 g of oxygen contain 1.75 moles.

3) Find the number of moles of argon in 452 g?

Answer:

11.31 mol

Explanation:

Given data:

Mass of argon = 452 g

Number of moles = ?

Solution:

Formula:

Number of moles = mass/ molar mass

Molar mass of argon= 39.95 g/mol

Now we will put the values in formula:

Number of moles = 452 g /39.95 g/mol

Number of moles = 11.31 mol

So 452 g of argon contain 11.31 moles.

2) What is the mass of 5.0 moles of iron?

Answer:

Mass = 279.25 g

Explanation:

Given data:

Mass of iron = ?

Number of moles of iron = 5.0 mol

Solution:

Formula:

Mass = number of moles × molar mass

Molar mass of iron = 55.85 g/mol

Now we will put the values in formula:

Mass = number of moles × molar mass

Mass = 5 mol × 55.85 g/mol

Mass = 279.25 g

4) Find the grams of 16.5 mole of hydrogen?

Answer:

Mass = 16.632 g

Explanation:

Given data:

Mass of hydrogen = ?

Number of moles of hydrogen = 16.5 mol

Solution:

Formula:

Mass = number of moles × molar mass

Molar mass of hydrogen = 1.008 g/mol

Now we will put the values in formula:

Mass = number of moles × molar mass

Mass = 16.5 × 1.008 g/mol

Mass = 16.632 g

7 0

3 years ago