Answer:
Explanation:
1) Convert 11.03 moles of calcium nitrate to grams.
Given data:
Number of moles = 11.03 mol
Mass of calcium nitrate = ?
Solution:
Formula:
Number of moles = mass / molar mass
Now we will rearrange the formula because we have to calculate the mass.
Mass = number of moles × molar mass
Molar mass of calcium nitrate = 164.088 g/mol
Mass = 11.03 mol × 164.088 g/mol
Mass = 1809.89 g
2. How many molecules are contained in 103.4g of sulfuric acid?
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
Given data:
Number of molecules = ?
Mass of sulfuric acid = 103.4 g
Solution:
Formula:
Number of moles = mass / molar mass
Number of moles = 103.4 g/ 98.079 g/mol
Number of moles = 1.05 mol
1 mole = 6.022 × 10²³ molecules
1.05 mol × 6.022 × 10²³ molecules / 1mol
6.323 × 10²³ molecules of sulfuric acid
3. 3.25 x 1024 molecules of dinitrogen pentoxide would be how many moles?
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
Given data:
Number of molecules of dinitrogen pentoxide = 3.25 × 10²⁴
Moles of dinitrogen pentoxide = ?
Solution:
1 mole = 6.022 × 10²³ molecules
1 mol × 3.25 × 10²⁴ molecules / 6.022 × 10²³ molecules
5.4 moles
4. What would be the mass of 9.03 x 1021 molecules of hydrobromic acid?
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
Given data:
Number of molecules of hydrobromic acid = 9.03 × 10²¹
Mass of hydrobromic acid = ?
Solution:
First of all we will calculate the moles of hydrobromic acid.
1 mole = 6.022 × 10²³ molecules
1 mol × 9.03 × 10²¹ molecules / 6.022 × 10²³ molecules
0.015 moles
Mass of hydrobromic acid:
Mass = number of moles × molar mass
Mass = 0.015 mol × 80.9 g/mol
Mass =1.21 g
5. A sample of iron (III) chloride has a mass of 26.29g. How many moles would this be?
Given data:
Number of moles =?
Mass of iron(III) chloride = 26.29 g
Solution:
Formula:
Number of moles = mass / molar mass
Molar mass of iron chloride = 162.2 g/mol
Now we will put the values in formula.
Moles = 26.29 g/ 162.2 g/mol
Moles = 0.16 g
= 8 mol H₂
