For an aqueous solution of MgBr2, a freezing point depression occurs due to the rules of colligative properties. Since MgBr2 is an ionic compound, it acts a strong electrolyte; thus, dissociating completely in an aqueous solution. For the equation:
ΔTf<span> = (K</span>f)(<span>m)(i)
</span>where:
ΔTf = change in freezing point = (Ti - Tf)
Ti = freezing point of pure water = 0 celsius
Tf = freezing point of water with solute = ?
Kf = freezing point depression constant = 1.86 celsius-kg/mole (for water)
m = molality of solution (mol solute/kg solvent) = ?
i = ions in solution = 3
Computing for molality:
Molar mass of MgBr2 = 184.113 g/mol
m = 10.5g MgBr2 / 184.113/ 0.2 kg water = 0.285 mol/kg
For the problem,
ΔTf = (Kf)(m)(i) = 1.86(0.285)(3) = 1.59 = Ti - Tf = 0 - Tf
Tf = -1.59 celsius
Answer:
B. wave 1 has a larger wavelength than wave 2
Answer:
seven electrons
Explanation:
Chlorine is present in group seventeen of periodic table. It is halogen element. All halogens have seven electrons in outer most valance shell.
The require only one electron to gain the stable electronic configuration or to complete the octet.
Electronic configuration of chlorine:
Cl₁₇ = 1s² 2s² 2p⁶ 3s² 3p⁵
Abbreviated electronic configuration:
Cl₁₇ = [Ne] 3s² 3p⁵
Properties of chlorine:
1. it is greenish-yellow irritating gas.
2. its melting point is 172.2 K
3. its boiling point is 238.6 K
4. it is disinfectant and can kill the bacteria.
5. it is also used in manufacturing of paper, paints and textile industries.
Answer:
sodium sulfate
Explanation:
For naming an ionic compound with polyatomic anion, the metal is written first using its element name followed by name of the polyatomic anion. Therefore, the compound with Na+Na+ cation and SO2−4SO42− anion is named as sodium sulfate.
The correct answer is: [A]: "<span>points with the same elevation" .
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