\(\color{blue} \text{V} = \text{n}\times 24 \text{ liter/mol}\)
Kondisi RTP (Room Temperature and Pressure) adalah kondisi gas pada saat suhu 25°C dan tekanan 1 atm. Pada kondisi RTP, 1 mol gas sama dengan 24 liter \(\text{V} = \text{volume molar gas (liter)}\) \(\text{n} = \text{jumlah mol gas (mol)}\)CONTOH SOAL
Soal 1 Sebanyak 1,6 gram gas oksigen berada dalam suatu wadah tertutup pada kondisi suhu 25°C dan tekanan 1 atm. Tentukan volume gas oksigen dalam wadah tersebut. (Ar O = 16).
\(\text{V} = \text{n}\times 24 \text{ liter/mol}\)
\(\text{V} = \dfrac{\text{massa oksigen}}{\text{Mr }\ce{O2}}\times 24 \text{ liter/mol}\)
\(\text{V} = \dfrac{1,6 \text{ gram}}{2 \times 16 \text{ gram/mol}}\times 24 \text{ liter/mol}\)
\(\text{V} = \dfrac{1,6}{32}\times 24 \text{ liter}\)
\(\text{V} = \dfrac{16}{320}\times 24 \text{ liter}\)
\(\text{V} = \dfrac{1}{20}\times 24 \text{ liter}\)
\(\text{V} = \dfrac{24}{20}\text{ liter}\)
\(\text{V} = 1,2 \text{ liter}\)
Gas etana = \(\ce{CH4}\)
\(\text{V} = \text{n}\times 24 \text{ liter/mol}\)
\(\text{V} = \dfrac{\text{massa gas metana}}{\text{Mr }\ce{CH4}}\times 24 \text{ liter/mol}\)
\(24 \text{ liter} = \dfrac{\text{massa gas metana}}{1 \times 12 + 4\times 1 \text{ gram/mol}}\times 24 \text{ liter/mol}\)
\(24 = \dfrac{\text{massa gas metana}}{16}\times 24\)
\(\cancel{24} = \dfrac{\text{massa gas metana}}{16}\times \cancel{24}\)
\(1 = \dfrac{\text{massa gas metana}}{16}\)
\(\text{massa gas metana} = 1 \times 16 \text{ gram}\)
\(\text{massa gas metana} = 16 \text{ gram}\)
Misal gas monoatomik tersebut = \(\ce{X}\)
\(\text{V} = \text{n}\times 24 \text{ liter/mol}\)
\(\text{V} = \dfrac{\text{massa gas}}{\text{Mr }\ce{X}}\times 24 \text{ liter/mol}\)
\(12 \text{ liter} = \dfrac{8}{\text{Ar X} \text{ gram/mol}}\times 24 \text{ liter/mol}\)
\(12 = \dfrac{8}{\text{Ar X}}\times 24 \)
\(\dfrac{12}{24} = \dfrac{8}{\text{Ar X}}\)
\(\dfrac{1}{2} = \dfrac{8}{\text{Ar X}}\)
Kalikan silang,
\(\text{Ar X} = 2 \times 8\)
\(\text{Ar X} = 16 \text{ gram/mol}\)
Jadi, massa atom relatif gas monoatomik tersebut adalah 16