How many molecules are in each of the following compounds or elements?

3) 9.273 x 10^7 grams of chromium (iii) bicarbonate

0.241  × 10³⁰ molecules

Explanation:

Given data:

Mass of Cr(HCO₃)₃ = 9.273 × 10⁷ g

Number of molecules = ?

Solution:

Number of moles = 9.273 × 10⁷ g/ 235 g/mol

Number of moles = 0.04× 10⁷  mol

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 0.04× 10⁷  moles of Cr(HCO₃)₃:

0.04× 10⁷  moles × 6.022 × 10²³ molecules / 1 mol

0.241  × 10³⁰ molecules

2fe + 3h2so4 -> fe2(so4)3 + 3h2

it is necessary to balance equations in order to get the proper amount of reactants as well as products in order not to make a miscalculation.

you cannot change the subscripts as that would change the substance itself. for instance, diatomic elements such as h2 only have the subscript two when a gas. another example would be so4, if you were to change the subscript, the element would no longer be sulfate.

we change the coefficients instead as that only changes the number of molecules rather than the substance itself.

hope this !