Answer:
c. 1.5 mol
Explanation:
- Firstly, we need to calculate the no, of moles of 39.0 grams of calcium fluoride.
n = mass / molar mass = (39.0 g) / (78.07 g/mol) = 0.499 mol ≅ 0.5 mol.
- CaF₂ ionized in water as:
<em>CaF₂ → Ca⁺² + 2F⁻.</em>
Every 0.1 mole of CaF₂ is ionized to 3 ions (1 ion of Ca⁺² and 2 ions of F⁻).
<em>So, 0.5 mol of CaF₂ will contain (3 x 0.5 mol = 1.5 mol) of ions.</em>
Thus, the right choice is "c. 1.5 mol".
Ionic solids—Made up of positive and negative ions and held together by electrostatic attractions. They're characterized by very high melting points and brittleness and are poor conductors in the solid state. An example of an ionic solid is table salt, NaCl.
multimeter is an electronic instrument used to measure the three basic electrical characteristics: voltage, current and resistance. It has multiple functions and acts like ohmmeter, voltmeter and ammeter and also used for household wiring, electric motors, testing batteries and power supplies.
The correct answer is the last option. Active metals will not react with acids in double replacement reactions. Instead, it reacts with metals via sing replacement reactions. It will displace hydrogen from the acid.