Convert 18g of Li into atoms.

Which of the following (with specific heat capacity provided) would show the smallest temperature change upon gaining 200.0 J of

Brut [27]

Answer: The smallest temperature change is shown by water.

Explanation:

To calculate the heat absorbed or released, we use the equation:

$q=mC\times \Delta T$ ......(1)

where,

q = heat absorbed = 200.0 J

m = mass of the substance

C = specific heat of substance

$\Delta T$ = change in temperature

As, the same amount of heat is getting absorbed in all the cases. So, the change in temperature will depend on the product of mass and specific heat.

For the given options:

Option a: 50.0 g Fe, $C_{Fe}=0.449J/g^oC$

We are given:

$m=50.0g\\C_{Fe}=0.449J/g^oC$

Putting values in equation 1, we get:

$200.0J=50.0g\times 0.449J/g^oC\times \Delta T\\\\\Delta T=\frac{200}{50\times 0.449}=8.99^oC$

Change in temperature = 8.99°C

Option b: 50.0 g water, $C_{water}=4.18J/g^oC$

We are given:

$m=50.0g\\C_{water}=4.18J/g^oC$

Putting values in equation 1, we get:

$200.0J=50.0g\times 4.18J/g^oC\times \Delta T\\\\\Delta T=\frac{200}{50\times 4.18}=0.96^oC$

Change in temperature = 0.96°C

Option b: 25.0 g Pb, $C_{Pb}=0.128J/g^oC$

We are given:

$m=50.0g\\C_{Pb}=0.128J/g^oC$

Putting values in equation 1, we get:

$200.0J=25.0g\times 0.128J/g^oC\times \Delta T\\\\\Delta T=\frac{200}{25\times 0.128}=62.5^oC$

Change in temperature = 62.5°C

Option d: 25.0 g Ag, $C_{Ag}=0.235J/g^oC$

We are given:

$m=25.0g\\C_{Ag}=0.235J/g^oC$

Putting values in equation 1, we get:

$200.0J=25.0g\times 0.235J/g^oC\times \Delta T\\\\\Delta T=\frac{200}{25\times 0.235}=34.04^oC$

Change in temperature = 34.04°C

Option e: 25.0 g granite, $C_{granite}=0.79J/g^oC$

We are given:

$m=25.0g\\C_{Fe}=0.79J/g^oC$

Putting values in equation 1, we get:

$200.0J=25.0g\times 0.79J/g^oC\times \Delta T\\\\\Delta T=\frac{200}{25\times 0.79}=10.13^oC$

Change in temperature = 10.13°C

Hence, the smallest temperature change is shown by water.

5 0

3 years ago

How did coroners handle their responsibilities in the early 1900s? Why was there a need for significant change in the job?

Lorico [155]

Answer:

In the twentieth century, criminologists and forensics strive to summarize the preceding discoveries. In different countries tendencies are beginning to manifest that increase the field of criminological activity in different branches such as criminalistics in Germany; others, penology; and others like the United States, weighed the study as a whole of the science of crime and the science of social reaction provoked by it. In this century, criminology and forensic science had a notable influence on the evolution of criminal law.

Starting in the mid-20th century, a paradigm shift in forensic criminological science was presented, focusing on the study of three aspects: criminal processes, the social environment, and the victim.

Other factors that were taken into account were biosecurity care, which began to have great relevance and greater care since they began to discover infectious diseases transmitted by cadavers to humans.

Approximately in 1939 it was discovered that anthropometric measurements are values that present similarities between different skeleton patterns.

Explanation:

Legal dentistry also addresses the aspect related to “professions” and people's habits, for example, by 1925 it was already possible to identify a smoker by the coloration that the teeth took and the wear on the incisors and canines where the cigar rested. The morphological characteristics of the teeth were, in many cases, used to identify those they called "degenerates", who were the ones who went outside the guidelines of psychic "normality" of the time; among these were prostitutes, thieves, who according to the author had a considerable volume in the molars, the canines were triangular and long, like the upper central incisors that in some reached 8 mm.

3 0

3 years ago

A solution of acetic acid has a pH of 3.45. What is the concentration of acetic acid in this solution? Ka for CH3COOH is 1.8×10-

Serjik [45]

Answer:

0.007 M

Explanation:

pH is defined as the negative logarithm of the concentration of hydrogen ions.

Thus,

pH = - log [H⁺]

The expression of the pH of the calculation of weak acid is:-

$pH=-log(\sqrt{k_a\times C})$

Where, C is the concentration = ?

Given, pH = 3.45

So, for $CH_3COOH$ , $K_a=1.8\times 10^{-5}$

$3.45=-log(\sqrt{1.8\times 10^{-5}\times C})$

$\log _{10}\left(\sqrt{1.8\cdot \:10^{-5}C}\right)=-3.45$

C = 0.007 M

5 0

3 years ago

Help me with this chemistry question please.

rodikova [14]

Answer:

B) Because you are adding positively charged protons, which pull in the outer electrons.

Explanation:

Since the increase in protons have a greater effect then the increase in electrons the protons pull the electrons in closer resulting the radius of an atom to decrease from left to right across a period.

4 0

3 years ago

Consider an AB3 molecule in which A and B differ in elec-tronegativity. You are told that the molecule has an over-all dipole mo

Alborosie

Answer:

(b) Trigonal planar

Explanation:

The molecular geometry is the one that stabilizes better the bonds and the free electron pairs. If the molecule is nonpolar (overall dipole moment zero), so, there's no free electron pairs at the central atom. So, the molecule has the central atom A surrounded by three atoms of B, which is the trigonal planar geometry.

5 0

3 years ago