Answer:
(a) Covalent bond. NF₃ (nitrogen trifluoride)
(b) Ionic bond. LiCl (lithium chloride)
Explanation:
<em>(a) N and F</em>
Nitrogen and fluorine are nonmetals, with high and similar electronegativities, so they form covalent bonds, in which they share pairs of electrons to complete the octet in their valence shell. N has 5 valence electrons so it will form 3 covalent bonds while each Cl has 7 valence electrons so it will form 1 covalent bond. As a result, the empirical formula is NF₃ (nitrogen trifluoride).
<em>(b) Li and Cl</em>
Lithium is a metal and Chlorine is a nonmetal. They have different electronegativities so they form an ionic bond, in which Cl gains 1 electron (7 valence e⁻) and Li loses 1 electron (1 valence e⁻). The empirical formula is LiCl (lithium chloride).
Answer is: the combined ionic bond strength of CrCl₂ and intermolecular forces between water molecules.
When chromium chloride (CrCl₂) is dissolved in water, the temperature of the water increases, heat of the solution is endothermic.
Dissociation of chromium chloride in water: CrCl₂(aq) → Cr²⁺(aq) + 2Cl⁻(aq).
Energy (the lattice energy) is required to pull apart the oppositely charged ions in chromium chloride.
The heat of hydration is liberated energy when the separated ions (in this example chromium cations and chlorine anions) attract polar water molecules.
Because the lattice energy is higher than the heat of the hydration (endothermic reaction), we can conclude that bonds between ions are strong (the electrostatic attraction between oppositely charged ions).
Answer:
option no b is right answer
Answer:
A homogenous mixture is a mixture that is uniform in composition. This means that you cannot apart the individual elements that make up the mixture.
Explanation:
Answer: 1.24 × 10^25
Explanation:
× 
Using our knowledge in unit conversions, we know the mole units cancel each other out and all there's left is the atom unit. From here we can multiply the fractions and eventually we end with the number 124.0532 × 10^23
According to the scientific notation rules, the number to the left of the decimal cannot exceed 10 so we have to move the decimal to the left two spaces. With this change, we also have to change the exponent of the 10. Because we moved the decimal point two spaces to the left, that means we have 10^25.
