All categories

3 years ago

What is the definition of enthalpy heat of vaporization?

1 answer:

8 0

Enthalpy heat of vaporization is the measurement of heat required to convert an amount of substance from the liquid to the gas phase.

You might be interested in

What monatomic ions do selenium (z = 34) and phosphorus (z = 15) form? (type your answer using the format [cu]+ for cu+ and [cu]

Alex787 [66]

The answer:
for the monoatomic <span>selenium ions
</span> -the ion charge of selenium is 2-, so the answer is [Se]2+
as for the monoatomic phosphorus ions
-the ion charge of phosphorus is 3-, so the answer is [P]3-

6 0

3 years ago

The measured value 24.00 g has an uncertainty of?

Orlov [11]

Answer:

±0.005 g

Explanation:

The uncertainty depends on whether the measurement was obtained manually or digitally.

1. Manual

The minimum uncertainty is ±0.01 g.

It may be greater, depending on random or personal errors

2. Digital

Most measurements of mass are now made on digital scales.

A digital device must always round off the measurement it displays.

For example, if the display reads 20.00, the measurement must be between 20.005 and 19.995 (±0.005).

If the measured value were 20.006, the display would round up to 20.01.

If the measured value were 19.994, the display would round down to 19.99.

The uncertainty is ±0.005 g.

The scale shown below would display a mass of 20.00 g

6 0

3 years ago

For the solution resulting from dissolved 0.32 g of naphthalene (C10H8) in 25 g of benzene (C6H6) at temperature of 26.1°C, calc

grandymaker [24]

Answer:

See explanation

Explanation:

Number of moles of naphthalene = 0.32g/128.1705 g/mol = 0.0025 moles

Molality = number of moles/ mass of Solvent in kilograms

Molality = 0.0025/0.025 Kg

Morality = 0.1 m

But

∆T= K × i × m

Where ∆T = boiling point elevation

i= number of particles (this is equal to 1 because naphthalene is molecular and not ionic)

m= molality of naphthalene = 0.1 m

K= boiling point elevation constant = 5.12 °C/m

∆T= 5.12 °C/m ×0.1 = 0.512°C

For freezing point depression

∆T= K× i × m

Where ∆T= freezing point depression

i= number of particles (this is equal to 1 because naphthalene is molecular and not ionic)

m= molality of naphthalene = 0.1 m

K= freezing point depression constant = 2.67 °C/m

∆T= 2.67 °C/m ×0.1 = 0.267°C

From Raoult's law;

∆P = XBPA°

Where;

∆P = vapour pressure lowering

XB = mole fraction of solute

PA° = vapour pressure of pure solvent

Number of moles of solvent = mass/molar mass = 25g/ 78 g/mol= 0.3205 moles

Total number of moles = number of moles of solute + number of moles of solvent = 0.0025 moles + 0.3205 moles = 0.323 moles

Mole fraction of solute = 0.0025 moles/0.323 moles = 0.0077

Vapour pressure of benzene = 100 torr

Therefore;

∆P = 0.0077 × 100torr = 0.77 torr

Hence;

∆P = 0.77 torr

5 0

3 years ago

In a chemical reaction, water decomposes to form hydrogen and oxygen. What is the correct term for the water?

gulaghasi [49]

The answer is: [D]: a reactant.
________________________

7 0

3 years ago

Read 2 more answers

Identify and describe the different forms of precipitation shown in the images.

Nutka1998 [239]

Answer:

It was first just snow but now its snow ball eggs that's what it looks like hope it helps:)

Explanation:

4 0

2 years ago