Answer:
0.725 kg
Explanation:
Step 1: Given data
- Kinetic energy of the softball (K): 145 J
- Speed of the softball (v): 20.0 m/s
- Mass of the softball (m): ?
Step 2: Calculate the mass of the softball
We will use the following expression.
K = 1/2 × m × v²
m = 2 K / v²
m = 2 × 145 J / (20.0 m/s)²
m = 0.725 kg
The mass of the softball is 0.725 kg.
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:
sulfur will have a chafge of -2 and Lithium will have a charge of +1
The hydrogen bonds that form between water molecules account for some of the essential and unique properties of water. The attraction created by hydrogen bonds keepswater liquid over a wider range of temperature than is found for any other molecule its size.
Hope this helped!