Ask question

Ask question

All categories

2 years ago

5

The mass of sample x is 20.0g it was placed in a graduated cylinder and the water level to from a to b. What is the density of t

he sample x?

1 answer:

yawa3891 [41]2 years ago

4 0

Answer:

.

Explanation:

You might be interested in

Octane is a liquid component of gasoline. Given the following vapor pressures of octane at various temperatures, estimate the bo

Hitman42 [59]

Answer:

110.8 ºC

Explanation:

To solve this problem we will make use of the Clausius-Clayperon equation:

lnP = - ΔHºvap/RT + C

where P is the pressure, ΔHºvap is the enthalpy of vaporization, R is the gas constant, T is the temperature, and C is a constant of integration.

Now this equation has a form y = mx + b where

y = lnP

x = 1/T

m = -ΔHºvap/R

Now we have to assume that ΔHºvap remains constant which is a good asumption given the narrow range of temperatures in the data ( 104-125) ºC

Thus what we have to do is find the equation of the best fit for this data using a software as excel or your calculator.

T ( K) 1/T ln P

377 0.002653 5.9915

384 0.002604 6.2115

390 0.002564 6.3969

395 0.002532 6.5511

398 0.002513 6.6333

The best line has a fit:

y = -4609.5 x + 18.218

with R² = 0.9998

Now that we have the equation of the line, we simply will substitute for a pressure of 496 mm in Leadville.

ln(496) = -4609.5(1/Tb) + 18.218

6.2066 = -4609.5(1/Tb) +18.218

⇒ 1/Tb = (18.218 - 6.2066)/4609.5 = 0.00261

Tb = 383.76 K = (383.76 -273)K = 110.8 ºC

Notice we have touse up to 4 decimal places since rounding could lead to an erroneous answer ( i.e boiling temperature greater than 111, an impossibility given the data in the question). This is as a result of the value 496 mmHg so close to 500 mm Hg.

Perhaps that is the reason the question was flagged.

7 0

2 years ago

A gas that has a volume of 28 liters, a temperature of 45C, And an unknown pressure has its volume increased to 34 liters and it

patriot [66]

Answer:

P1 = 2.5ATM

Explanation:

V1 = 28L

T1 = 45°C = (45 + 273.15)K = 318.15K

V2 = 34L

T2 = 35°C = (35 + 273.15)K = 308.15K

P1 = ?

P2 = 2ATM

applying combined gas equation,

P1V1 / T1 = P2V2 / T2

P1*V1*T2 = P2*V2*T1

Solving for P1

P1 = P2*V2*T1 / V1*T2

P1 = (2.0 * 34 * 318.15) / (28 * 308.15)

P1 = 21634.2 / 8628.2

P1 = 2.5ATM

The initial pressure was 2.5ATM

3 0

2 years ago

A well-insulated, closed device claims to be able to compress 100 mol of propylene, acting as a SoaveRedlich-Kwong gas and with

Setler79 [48]

Explanation:

The given data is as follows.

Moles of propylene = 100 moles, $T_{i}$ = 300 K

$T_{f}$ = 800 K, $V_{i} = 2 m^{3}$

$V_{f} = 0.02 m^{3}$ , $C_{p}$ of propylene = 100 J/mol

Now, we assume the following assumptions:

Since, it is a compression process therefore, work will be done on the system. And, work done will be equal to the heat energy liberating without any friction.

W = $mC_{p} \Delta T$

$100 moles \times 100 J/mol K (800 - 300) K$

= $5 \times 10^{6} J$

= 5 MJ

Thus, we can conclude that a minimum of 5 MJ work is required without any friction.

3 0

2 years ago

List the salts in order from weakest to strongest lattice energy (most positive to most negative). magnesium chloride, barium ch

almond37 [142]

Answer: Option (6) is the correct answer.

Explanation:

Lattice energy is described as the energy released when formation of 1 mole of an ionic compound occurs due to the combination of its constituent ions.

Also, lattice energy is inversely proportional to the distance between the cation and anion. And, when we move down a group then there occurs an increase in the atomic radii of the atoms.

This means that smaller is the ionic distance between the cation and anion, more will be the lattice energy between the atoms.

Therefore, order from weakest to strongest lattice energy (most positive to most negative) for the given compounds is as follows.

barium chloride < strontium chloride < calcium chloride < magnesium chloride

6 0

2 years ago

A 1.0 x 102- gram sample is found to be pure alanine, an amino acid found in proteins. How many moles of alanine are in the samp

Romashka-Z-Leto [24]

Answer:

1.123x10⁻⁴ moles of alanine

Explanation:

In order to convert grams of alanine into moles, <em>we need to know its molecular weight</em>:

The formula for alanine is C₃H₇NO₂, meaning <u>its molecular weight would be</u>:

12*3 + 7*1 + 14 + 16*2 = 89 g/mol

Then we <u>divide the sample mass by the molecular weight</u>, to do the conversion:

1.0x10⁻² g ÷ 89 g/mol = 1.123x10⁻⁴ moles

4 0

2 years ago