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3 years ago

PLEASE HELP WITH ALL

Chemistry

2 answers:

Tpy6a [65]3 years ago

7 0

Answer:

Question 1: Correct 3 and 4

Question 2: All can be corrected except item 2.

Question 3: Correct 1

Question 4: Correct 1

Question 5: Correct 1

Explanation:

Question 1: The law of conservation of mass explains that “In an isolated system, during any ordinary chemical reaction, the total mass in the system remains constant, that is, the mass consumed of the reagents is equal to the mass of the products obtained”, therefore, statements 3 are correct, which tells us that we must begin and end with the same amount of matter, and 4, since we cannot create or destroy matter.

Question 2: When a chemical reaction occurs, according to the initial compounds (reagents), it can be seen in various ways how a change in the system occurs, which indicates that a chemical reaction occurred, many of them can be identify with our senses (change of color, change of temperature, change of state of aggregation of the reagents, etc.), it is clear that they do not have problems that have all these statements together, with which of these happen, we could affirm that it had a chemical reaction.

On the other hand, changes that can be easily undone (affirmation 2) are more related to physical phenomena, in which the intimate composition of matter (such as a change of state) does not vary, a difference in chemical reactions .

Question 3: When a chemical reaction occurs, the substances that are initially found (reagents) change the intimate structure of matter, breaking and / or forming bonds of the compounds to form new bonds, and thus, new substances (products). That is why the correct statement is 1, in the case of the other statements, physical phenomena are being described, in which there are no breaking of bonds in the initial compounds to form new substances, simply, state changes occur in matter, but no new compounds are formed.

Question 4: In changes of state, there are no changes in the intimate structure of matter, so they are physical phenomena. The only thing that varies in the changes of state of matter, is the kinetic energy with which the particles of the system move, due to the variation in temperature.

Question 5: Unlike physical reactions, in chemical reactions there are bond ruptures and / or rearrangement of atoms of the initial compounds (reagents) to form new bonds and structures, and thus, new compounds (reaction products). In addition, these reactions comply with the law of conservation of mass, so that matter cannot be created or destroyed, as well as energy.

Gala2k [10]3 years ago

5 0

Answer:

Question 1: D

Question 2: B C E F

Question 3: A

Question 4: A

Question 5: A

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A plastic bin is found to hold 3.1x10^24 molecules of water.

motikmotik

Answer:

$\boxed {\boxed {\sf 5.1 \ mol \ H_2O}}$

Explanation:

To convert from representative particles to moles, Avogadro's Number: 6.02*10²³, which tells us the number of particles (atoms, molecules, etc.) in 1 mole of a substance.

We can use it in a ratio.

$\frac {6.02*10^{23} \ molecules \ H_2O}{1 \ mol \ H_2O}$

Multiply by the given number of molecules.

$3.1*10^{24} \ molecules \ H_2O*\frac {6.02*10^{23} \ molecules \ H_2O}{1 \ mol \ H_2O}$

Flip the ratio so the molecules of water cancel out.

$3.1*10^{24} \ molecules \ H_2O*\frac {1 \ mol \ H_2O}{6.02*10^{23} \ molecules \ H_2O}$

$3.1*10^{24} *\frac {1 \ mol \ H_2O}{6.02*10^{23} }$

$\frac {3.1*10^{24} \ mol \ H_2O}{6.02*10^{23} }$

Divide.

$5.14950166113 \ mol \ H_2O$

The original number of molecules has 2 significant figures: 3 and 1, so our answer must have the same. For the number we calculated, that is the tenth place. The 4 in the hundredth place tells us to leave the 1.

$5.1 \ mol \ H_2O$

There are about 5.1 moles of water in 3.1*10²⁴ molecules of water.

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2 years ago

What did Bohr’s model focus on that Rutherford’s model did not?

wlad13 [49]

Answer:

Because Rutherford's model was weak on the position of the electrons, Bohr focused on them. He hypothesized that electrons can move around the nucleus only at fixed distances from the nucleus based on the amount of energy they have. ... However, an electron could never exist in between two energy levels

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3 years ago

Please help with question 4 and 5 please!!

ratelena [41]

Question four is : Gaseous state

Question five is : A rise in temperature increases the kinetic energy and speed of particles; it does not weaken the forces between them. The particles in solids vibrate about fixed positions; even at very low temperatures. Individual particles in liquids and gases have no fixed positions and move chaotically.

Hope this helps!

Have a great day!

8 0

3 years ago

If a gas occupies a volume of 950 mL at standard temperature, what volume will it

n200080 [17]

Voulme 1= 950 mL
Volume 2= ?
Temperature 1 = 25 C
Temperature 2 = 50 C
Convert your temperature to Kelvin
C+273=K
Temperature 1 = 25 C + 273 = 298 K
Temperature 2 = 50 C + 273 = 323 K

Plug in to the Formula
950 mL/298 K = ? / 323 K

Rearrange the formula to make one to solve for what is missing.
To get 323 K out of the denominator multiply by it.
Making it
950 mL x 323 K / 298 K = ?

Plug it in
950 mL x 323 K / 298 K = 1027.9 mL

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3 years ago

1 lb of CO2 occupies 0.6 ft^3 at a pressure of 200 psi. Determine the temperature of the system.

Anarel [89]

Answer: The temperature of the system is 273 K

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$