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1 year ago

!!!!100 POINTS!!!!

Chemistry

1 answer:

Cerrena [4.2K]1 year ago

6 0

The research of astronomy during the time period of 1970 - 1990 is given below:

<u>Date</u> <u>Event</u>

1. 15 June 1974 Black Brant VC sounding rocket from White Sands.

2. 14 May 1973 Launch of Skylab, the USA's first space station

3. 26 July 1971 Launch of Apollo 15

<h3>What is Astronomy?</h3>

This refers to the branch of science that deals with celestial bodies and their relation to each other.

Hence, from information about astronomy, between the time period 1970 - 1990 as it was on the 26th of December, 1974 that the Soviet space station Salyut-4 was launched.

The event I think had the greatest impact in astronomical history during this time period was the launch of Apollo 16.

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Under constant pressure a sample of hydrogen gas initially at 88°C and 9.6 L is cooled until its final volume is 3.4 L. What is

Scilla [17]

The final temperature = -145.24K or 127°C.

According to the data given,

T1= 88°C = 361.15K

V1= 9.6 L

V2= 3.4 L

T2= ?

We know that, according to Charles's law,

T1/V1=T2/V2

T2= T1*V2/V1

T2= 127°C or -145.24K

The final temperature = -145.24K or 127°C

<h3>What does Charles law state?</h3>

According to Charles' law, when the pressure is held constant, the volume of a given amount of gas is precisely proportional to its temperature on the kelvin scale.

<h3>What connection exists between volume and temperature?</h3>

In layman's words, the volume of a fixed mass of gas is exactly proportional to temperature at constant pressure.
When a constant mass of gas is cooled, its volume decreases, and when the temperature is elevated, its volume grows.

<h3>What are the applications of Charles law?</h3>

A hot air balloon drifting through the air is an illustration of Charles Law in action.
The air within the balloon is heated by a torch, which causes the air molecules to move more quickly and disperse.
This causes the air inside the balloon to be less dense than the air outside, which causes the balloon to float.

To learn more about Charles law visit:

brainly.com/question/16927784

#SPJ9

7 0

1 year ago

4). One mole of monoclinic sulfur at 25C was placed in a constant-pressure calorimeter whose heat capacity (C) was 1620 J/K. T

andre [41]

<u>Answer:</u> The enthalpy change of the reaction is -243 J/mol

<u>Explanation:</u>

The heat released by the reaction is absorbed by the calorimeter and the solution.

The chemical equation used to calculate the heat released follows:

$q=c\times \Delta T$

where,

c = heat capacity of calorimeter = 1620 J/K

$\Delta T$ = change in temperature = $0.150^oC=0.150K$ (Change remains same)

Putting values in above equation, we get:

$q=1620J/K\times 0.15K=243J$

<u>Sign convention of heat:</u>

When heat is absorbed, the sign of heat is taken to be positive and when heat is released, the sign of heat is taken to be negative.

For the given chemical reaction:

$S\text{ (monoclinic)}\rightarrow S\text{ (orthorhombic)}$

We are given:

Moles of monoclinic sulfur = 1 mole

To calculate the enthalpy change of the reaction, we use the equation:

$\Delta H_{rxn}=\frac{q}{n}$

where,

q = amount of heat released = -243 J

n = number of moles = 1 mole

$\Delta H_{rxn}$ = enthalpy change of the reaction

Putting values in above equation, we get:

$\Delta H_{rxn}=\frac{-243J}{1mol}=-243J/mol$

Hence, the enthalpy change of the reaction is -243 J/mol

8 0

3 years ago

The person writes a coefficient of 2 in front of Fe2O3 but then writes a 4 for the number of iron (Fe) atoms. Explain this diffe

den301095 [7]

Answer:

See explanation

Explanation:

Given that the formula of the compound is Fe2O3, if a coefficient of 2 is placed in front of the formula, that is, if we write 2Fe2O3 . Then;

The number of Fe atoms becomes 2 *2 = 4

The number of oxygen atoms becomes 2*3 = 6

That is why the total number of iron atoms were written down as 4.

6 0

3 years ago

Read 2 more answers

Determine the direction that each of the reactions will progress. Assume that the reactants and products are present in equimola

xxMikexx [17]

Answer:

It would move either left or right

Explanation: Taking assumption that,

Fructose + ATP fructose - 6 - phosphate + ADP (The standard free energy of hydrolysis for fructose-6-phosphate is - 15.9 kJ/mol.) 3 - phosphoglycerate + ATP 1,3 - bisphosphoglycerate + ADP (The standard free energy of hydrolysis for 1,3-bisphosphoglycerate is - 4 9.3 kJ/mol.) pyruvate + ATP phosphoenolpyruvate + ADP (The standard free energy of hydrolysis for phosphoenolpyruvate -is -61.9 kJ/mol.)

8 0

2 years ago

Electrons must be able to flow through a material in order for the material to conduct

djverab [1.8K]

The molecular structure of the solids has lower ability to conduct electricity due to tight holding by nucleus.

<h3>Why molecular solids are poor conductors?</h3>

Molecular solids are also poor conductors of electricity because their valence electrons are tightly held by the nuclear charges present in the nucleus while on the other hand, Metals are good electrical conductors in the solid form due to the presence of free electrons that helps in the conduction of electricity.

Learn more about electricity here: brainly.com/question/25144822

7 0

2 years ago