Question

monday: convert 25g of mgcl₂ to atoms.

Explanation:

Step1: Calculate molar mass of MgCl₂

The molar mass of Mg is approximately 24.31 g/mol, and Cl is approximately 35.45 g/mol. For MgCl₂, molar mass $M = 24.31+2\times35.45= 95.21$ g/mol.

Step2: Calculate number of moles

The number of moles $n$ of MgCl₂ is given by the formula $n=\frac{m}{M}$, where $m = 25$ g and $M = 95.21$ g/mol. So $n=\frac{25}{95.21}\approx0.263$ mol.

Step3: Calculate number of formula - units

Using Avogadro's number $N_A = 6.022\times 10^{23}$ formula - units/mol, the number of formula - units of MgCl₂ is $N=n\times N_A=0.263\times6.022\times 10^{23}\approx1.584\times 10^{23}$ formula - units.

Step4: Calculate number of atoms

In one formula - unit of MgCl₂, there are 3 atoms (1 Mg and 2 Cl). So the number of atoms $=3\times1.584\times 10^{23}=4.752\times 10^{23}$ atoms.

Answer:

$4.752\times 10^{23}$ atoms