Pupil sheet · The mole
The mole — return questions
Name ______________________ Date ____________
Use one to two weeks after the lessons. Keep the notes and the lesson closed.
1. state
Supplement. The table shows three facts about the mole. Which row is correct?
| Row | The mole is the unit of | One mole contains | This number is called |
|---|---|---|---|
| A | concentration | 6.02 × 10²³ particles | the Avogadro constant |
| B | amount of substance | 6.02 × 10²³ particles | the Avogadro constant |
| C | amount of substance | 6.02 × 10²³ grams | the Avogadro constant |
| D | amount of substance | 6.02 × 10²³ particles | the molar mass |
Circle one answer.
- A
- B
- C
- D
2. calculate / deduce / identify
Supplement. An element X forms a chloride with the formula XCl2. 0.0300 mol of XCl2 has a mass of 3.81 g. (Ar: Cl 35.5.) Which row gives the molar mass of XCl2, the relative atomic mass of X and the element X?
| Row | Molar mass of XCl2 | Relative atomic mass of X | Element X |
|---|---|---|---|
| A | 127 g/mol | 127 | iodine |
| B | 127 | 56 g/mol | iron |
| C | 127 g/mol | 91.5 | zirconium |
| D | 127 g/mol | 56 | iron |
Circle one answer.
- A
- B
- C
- D
3. calculate
Supplement. 1.46 g of hydrogen chloride, HCl, is dissolved in water to make 50.0 cm³ of hydrochloric acid. (Ar: H 1, Cl 35.5.) Calculate (a) the concentration in g/dm³, (b) the concentration in mol/dm³. Give each calculated answer to three significant figures.
(a) Concentration in g/dm³: ______________ unit ________
(b) Concentration in mol/dm³: ______________ unit ________
4. state
A technician has four bottles of potassium iodide. Which label gives the concentration of the solution?
Circle one answer.
- Potassium iodide, 166 g/mol
- Potassium iodide solution, 0.0500 mol
- Potassium iodide solution, 500 cm³
- Potassium iodide solution, 8.30 g/dm³