Sec 3 Pure Chemistry Moles and Stoichiometry Formulas

Comprehensive practice flashcards covering all core formulas for Sec 3 Pure Chemistry Moles and Stoichiometry, including mass-mole relations, gas volume calculations, and solution concentration conversions.

What is the formula to find the number of moles ($n$) using mass and molar mass ($M_r$)?

$$n = \frac{\text{Mass (g)}}{M_r}$$

How is Mass (g) calculated when the number of moles ($n$) and molar mass ($M_r$) are known?

$$\text{Mass (g)} = n \times M_r$$

What is the formula to determine the Molar Mass ($M_r$) from mass and moles?

$$M_r = \frac{\text{Mass (g)}}{n}$$

What is the formula for the number of moles ($n$) of a gas when the volume is given in $dm^3$?

$$n = \frac{\text{Volume}}{24}$$

How is the volume of a gas in $dm^3$ calculated from the number of moles ($n$)?

$$\text{Volume (dm}^3\text{)} = n \times 24$$

What is the value of the Molar Gas Volume constant when using $dm^3$?

$$24$$

What is the formula for the number of moles ($n$) of a gas when the volume is given in $cm^3$?

$$n = \frac{\text{Volume}}{24000}$$

How is the volume of a gas in $cm^3$ calculated from the number of moles ($n$)?

$$\text{Volume (cm}^3\text{)} = n \times 24000$$

What is the value of the Molar Gas Volume constant when using $cm^3$?

$$24000$$

What is the formula to find the number of moles ($n$) in a solution using concentration and volume?

$$n = \text{Conc (mol/dm}^3\text{)} \times \text{Vol (dm}^3\text{)}$$

How is Concentration in $\text{mol/dm}^3$ calculated?

$$\text{Conc (mol/dm}^3\text{)} = \frac{n}{\text{Vol (dm}^3\text{)}}$$

What is the formula to find the Volume ($dm^3$) of a solution?

$$\text{Volume} = \frac{n}{\text{Conc (mol/dm}^3\text{)}}$$

What is the formula to convert concentration from $\text{mol/dm}^3$ to $\text{g/dm}^3$?

$$\text{Conc (g/dm}^3\text{)} = \text{Conc (mol/dm}^3\text{)} \times M_r$$

What is the formula to convert concentration from $\text{g/dm}^3$ to $\text{mol/dm}^3$?

$$\text{Conc (mol/dm}^3\text{)} = \frac{\text{Conc (g/dm}^3\text{)}}{M_r}$$