Answer:
8.13 ×10²³ atoms
Explanation:
Given data:
Mass of magnesium = 32.45 g
Number of atoms = ?
Solution:
Number of moles of Mg:
Number of moles = mass/molar mass
Number of moles = 32.45 g/ 24 g/mol
Number of moles = 1.35 mol
Number of atoms:
1 mole contain 6.022×10²³ atoms
1.35 mol × 6.022×10²³ atoms/ 1mol
8.13 ×10²³ atoms
Repeat trials multiple times
Once you identify the compound as Ionic<span>, </span>Molecular, or an Acid, follow the individual ... chemicalformulas<span>, write </span>whether<span> the compound is </span>ionic or molecular<span>, and ...</span>
Answer:
In the previous section, we discussed the relationship between the bulk mass of a substance and the number of atoms or molecules it contains (moles). Given the chemical formula of the substance, we were able to determine the amount of the substance (moles) from its mass, and vice versa. But what if the chemical formula of a substance is unknown? In this section, we will explore how to apply these very same principles in order to derive the chemical formulas of unknown substances from experimental mass measurements.
Explanation:
tally. The results of these measurements permit the calculation of the compound’s percent composition, defined as the percentage by mass of each element in the compound. For example, consider a gaseous compound composed solely of carbon and hydrogen. The percent composition of this compound could be represented as follows:
\displaystyle \%\text{H}=\frac{\text{mass H}}{\text{mass compound}}\times 100\%%H=
mass compound
mass H
×100%
\displaystyle \%\text{C}=\frac{\text{mass C}}{\text{mass compound}}\times 100\%%C=
mass compound
mass C
×100%
If analysis of a 10.0-g sample of this gas showed it to contain 2.5 g H and 7.5 g C, the percent composition would be calculated to be 25% H and 75% C:
\displaystyle \%\text{H}=\frac{2.5\text{g H}}{10.0\text{g compound}}\times 100\%=25\%%H=
10.0g compound
2.5g H
×100%=25%
\displaystyle \%\text{C}=\frac{7.5\text{g C}}{10.0\text{g compound}}\times 100\%=75\%%C=
10.0g compound
7.5g C
×100%=75%
