Analyze the following blood splatter pictures to determine the general direction, origin, and impact

Three kilograms of steam is contained in a horizontal, frictionless piston and the cylinder is heated at a constant pressure of

lakkis [162]

Answer:

Final temperature: 659.8ºC

Expansion work: 3*75=225 kJ

Internal energy change: 275 kJ

Explanation:

First, considering both initial and final states, write the energy balance:

$U_{2}-U_{1}=Q-W$

Q is the only variable known. To determine the work, it is possible to consider the reversible process; the work done on a expansion reversible process may be calculated as:

$dw=Pdv$

The pressure is constant, so: $w=P(v_{2}-v_{1} )=0.5*100*1.5=75\frac{kJ}{kg}$ (There is a multiplication by 100 due to the conversion of bar to kPa)

So, the internal energy change may be calculated from the energy balance (don't forget to multiply by the mass):

$U_{2}-U_{1}=500-(3*75)=275kJ$

On the other hand, due to the low pressure the ideal gas law may be appropriate. The ideal gas law is written for both states:

$P_{1}V_{1}=nRT_{1}$

$P_{2}V_{2}=nRT_{2}\\V_{2}=2.5V_{1}\\P_{2}=P_{1}\\2.5P_{1}V_{1}=nRT_{2}$

Subtracting the first from the second:

$1.5P_{1}V_{1}=nR(T_{2}-T_{1})$

Isolating $T_{2}$ :

$T_{2}=T_{1}+\frac{1.5P_{1}V_{1}}{nR}$

Assuming that it is water steam, n=0.1666 kmol

$V_{1}=\frac{nRT_{1}}{P_{1}}=\frac{8.314*0.1666*373.15}{500} =1.034m^{3}$

$T_{2}=100+\frac{1.5*500*1.034}{0.1666*8.314}=659.76$ ºC

7 0

3 years ago

The main factor that influences the direction of any periodic trend across a period is ______.

aalyn [17]

Answer:

The correct option is B

Explanation:

The number of valence electron(s) increases across the period and thus influences the direction of periodic trend of electronegativity, electron affinity and ionization energy across the period. Thus, making option B the answer.

It should be noted that option A is wrong because elements in the same period generally have the same number of electron shells and thus the distance of this shells from the nucleus remains the same throughout the same period and thus option C is also wrong. Option D is wrong because the periodic trends have to do with chemical reactions which actually involves electrons and not protons.

3 0

3 years ago

Pick the correct products for the following reaction acid + metal reaction: 2 HNO3 + Co -->

MrMuchimi

Answer:

2. Co(NO3)2 + H2

Explanation:

Hello,

In this case, we are evidencing a simple displacement reaction wherein the cobalt is able displace the hydrogen to produce cobalt (II) nitrate and gaseous hydrogen as a result of cobalt's higher activity:

$2 HNO_3 + Co\rightarrow Co(NO_3)_2+H_2$

Therefore, answer is 2. Co(NO3)2 + H2.

Best regards.

3 0

3 years ago

Read 2 more answers

What is a valency according to chemistry<br>

Bond [772]

Answer:

Valency is the measure of the combining power of an element

4 0

2 years ago

A 1.10 mol sample of krypton gas is collected at a pressure of 427 mmHg and a temperature of 6.0°C. The volume of the sample is

Aleksandr [31]

Answer:

Volume = 44.96L

Explanation:

p = 427mmHg = 0.56atm

R = 0.08206

T 6°C = 279k

V = ?

n = 1.10 mol

using ideal gas equation

pv=nRT

0.56 x V = 1.10 x 0.08206 x 279

0.56 x V = 25.18

V = 25.18/0.56

V = 44.96L

6 0

3 years ago