How many particles are in 4.5 moles of beryllium carbonate

27.099 × 10²³ particles

Explanation:

Given data:

Number of moles = 4.5 mol

Number of particles = ?

Solution;

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 Beryllium carbonate:

1 mole of Beryllium carbonate =  6.022 × 10²³ particles

4.5 mol  ×  6.022 × 10²³ particles / 1 mol

27.099 × 10²³ particles

there is none because earth is stationary and flat.

answer : third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol

explanation :

let us write down the given equations

equation 1 :

equation 2 :

equation 3 :

let us use hess's law to find out which 2 equations can be added to get the third equation.

let us reverse equation 2 and multiply it by 2. the new equation that we get is,

equation 4 :

let us add equation 1 & 4

the above equation is similar to equation 3 but has different value for dhrxn.

therefore third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol