Answer: 2.04L
Explanation:
coldest temperature = -10°C
mass of solvent = 6.50kg
freezing point depression = kb*m
Where kb = molar freezing point depression constant, 1.86
10 = 1.86 * molality of ethylene glycol
10 = 1.86 * moles of ethylene glycol/mass of solvent
10 = 1.86 * moles of ethylene glycol/6.5
10*6.5 = 1.86 * moles of ethylene glycol
Moles of ethylene glycol = 65/1.86
Moles of ethylene glycol = 36.11
36.11 mol * 62.1 g/mol = 2242.43g = 2.24kg
1 L = 1000 mL x 1.11 g/mL = 1100 g = 1.1 kg
2.24 kg / 1.10 kg/L = 2.04 L
7200sec÷60sec in a minute÷60minutes in an hour=2hours. 150km÷ 2 hours= 75 km/hour
Answer:
- Compress
- Fixed
- Melts
- Melting Point
- Freezing Point
- High
- Crystalline
- Lattice
- Unit cell
- Amorphous solids
Explanation:
Solids tend to be dense and difficult to <u>compress.</u>
They do not flow or take the shape of their containers, like liquids do, because the particles in solids vibrate around <u>fixed</u> points.
When a solid is heated until its particles vibrate so rapidly that they are no longer held in fixed positions, the solid <u>melts</u>.
<u>Melting point</u> is the temperature at which a solid changes to a liquid. The melting and <u>freezing point</u> of a substance are at the same temperature.
In general, ionic solids tend to have relatively <u>high</u> melting points, while molecular solids tend to have relatively low melting points.
Most solids are <u>crystalline</u>
The particles are arranged in a pattern known as a crystal <u>lattice</u>
The smallest subunit of a crystal lattice is the <u>unit cell</u>
Some solids lack an ordered internal structure and are called <u>amorphous solids.</u>
Answer:
Substances can change phase—often because of a temperature change. At low temperatures, most substances are solid; as the temperature increases, they become liquid; at higher temperatures still, they become gaseous.
The process of a solid becoming a liquid is called melting. (an older term that you may see sometimes is fusion). The opposite process, a liquid becoming a solid, is called solidification. For any pure substance, the temperature at which melting occurs—known as the melting point—is a characteristic of that substance. It requires energy for a solid to melt into a liquid. Every pure substance has a certain amount of energy it needs to change from a solid to a liquid. This amount is called the enthalpy of fusion (or heat of fusion) of the substance, represented as ΔHfus. Some ΔHfus values are listed in Table 10.2 “Enthalpies of Fusion for Various Substances”; it is assumed that these values are for the melting point of the substance. Note that the unit of ΔHfus is kilojoules per mole, so we need to know the quantity of material to know how much energy is involved. The ΔHfus is always tabulated as a positive number. However, it can be used for both the melting and the solidification processes as long as you keep in mind that melting is always endothermic (so ΔH will be positive), while solidification is always exothermic (so ΔH will be negative).