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3 years ago

According to the law of conservation of matter, what cannot change during a chemical reaction?.

1 answer:

7 0

Answer:The law of conservation of mass states that in a chemical reaction mass is neither created nor destroyed. ... The carbon atom changes from a solid structure to a gas but its mass does not change. Similarly, the law of conservation of energy states that the amount of energy is neither created nor destroyed.

Explanation:

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Kira dissolved different solutes in 100 ml of water. She recorded the amount of each solute that would dissolve at different tem

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This information confirms that temperature and solubility are related. The higher the temperature is, the more soluble.

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2 years ago

I NEED HELP!!!!!

wlad13 [49]

Answer: See explanation

Explanation:

The negative effects of video games include:

1. Social disconnection- One negative effect of video games is that it brings about social disconnection. Video games are typically addictive and this leads to the individual playing the game gradually disconnecting from the social life. Such people tends to play games rather than having conversations with their friends or family members.

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4. Negative academic achievement - Students who play video games a lot tend to have a negative academic achievement as the time they could have used in reading or studying is used for playing games and thus tends to have an effect on the performance in school.

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The positive effect of video games are:

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8 0

3 years ago

antimony has two naturally occuring isotopes, sb121sb121 and sb123sb123 . sb121sb121 has an atomic mass of 120.9038 u120.9038 u

Luda [366]

Considering the definition of atomic mass, isotopes and atomic mass of an element, sb121 has a percent natural abundance of 0.5726 or 57.26% and sb123 has a percent natural abundance of 0.4284 or 42.84%.

<h3>Definition of atomic mass</h3>

The atomic mass is obtained by adding the number of protons and neutrons in a given nucleus of a chemical element.

<h3>Definition of isotope</h3>

Isotopes are the chemical elements in which atomic numbers are the same, but the number of neutrons is different.

<h3>Definition of atomic mass</h3>

The atomic mass of an element is the weighted average mass of its natural isotopes.

This is, the atomic masses of elements are usually calculated as the weighted average of the masses of the different isotopes of each element, considering the relative abundance of each of them.

<h3>Percent natural abundance of each isotope</h3>

In this case, antimony has two naturally occuring isotopes, sb121 and sb123. You know:

sb121 has an atomic mass of 120.9038 u.
sb121 has a percent natural abundance of x.
sb123 has an atomic mass of 122.9042 u.
sb123 has a percent natural abundance of 1 -x (or, what is the same, the abundance is 100% - x%, since both isotopes form 100% of the element.)
Antimony has an average atomic mass of 121.7601 u

The average mass of antimony is expressed as:

121.7601 u= 120.9038 u x + 122.9042 u× (1 -x)

Solving:

121.7601 u= 120.9038 u x + 122.9042 u - 122.9042 u x

121.7601 u - 122.9042 u= 120.9038 u x - 122.9042 u x

(-1.1441 u)= (-2.0014) x

(-1.1441 u)÷ (-2.0014)= x

So, 1 -x= 1- 0.5716 → <u><em>1-x= 0.4284 or 42.84%</em></u>

Finally, sb121 has a percent natural abundance of 0.5726 or 57.26% and sb123 has a percent natural abundance of 0.4284 or 42.84%.

Learn more about average atomic mass:

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5 0

2 years ago

Why are changes in phase physical changes?

ehidna [41]

Weathering and chemical substance weathering

3 0

3 years ago

PLEASE HELP ASAP !!

Ivenika [448]

Answer:

2SO₂ + O₂ + 2H₂O -----------> 2H₂SO₄

Theoretical yield of H₂SO₄ = 213 g

percent yield of H₂SO₄ = 94 %

Explanation:

Data Given:

volume of SO₂ = 48.6 L

mass of H₂SO₄ = 200 g

balance equation = ?

theoretical yield = ?

percent yield = ?

Solution:

Part 1:

first we have to write a balance equation for the reaction

SO₂ gas react with water (H₂O) and excess oxygen

The balanced equation is as under

2SO₂ + O₂ + 2H₂O -----------> 2H₂SO₄

Part 2:

Now we have to find theoretical yield

First look at the balance reaction

2SO₂ + O₂ + 2H₂O -----------> 2H₂SO₄

2 mol 2 mol

2 moles of SO₂ give gives 2 moles of H₂SO₄

Now calculate volume of 2 moles of SO₂ and mass of 2 moles of H₂SO₄

volume of 2 moles of SO₂

Formula used

volume of gas = no. of moles x molar volume . . . . . . (1)

molar volume of SO₂= 22.4 L/mol

Put values in above formula (1)

volume of gas = 2 mol x 22.4 L/mol

volume of gas = 44.8 L

volume of 2 mole of SO₂ = 44.8 L

Now,

Find mass of 2 mole H₂SO₄

Formula Used

mass in grams = no. of moles x molar mass . . . . . . . (2)

molar mass of H₂SO₄ = 2 (1) + 32 + 4(16)

molar mass of H₂SO₄ = 98 g/mol

put values in equation 2

mass in grams = 2 mol x 98 g/mol

mass in grams = 196 g

mass of 2 mole of H₂SO₄ = 196 g

** So,

Now we come to know that

44.8 L of SO₂ gives 196 g of H₂SO₄ then how many grams of the H₂SO₄ will be produced by 48.6 L of SO₂

Apply unity Formula

44.8 L of SO₂ ≅ 196 g of H₂SO₄

48.6 L of SO₂ ≅ X g of H₂SO₄

Do cross multiplication

g of H₂SO₄ = 196 g x 48.6 L / 44.8 L

g of H₂SO₄ = 213 g

So that is why the theoretical yield of H₂SO₄ is 213 g

Theoretical yield of H₂SO₄ = 213 g

Part 3

Calculate Percent Yield:

Formula used for this purpose:

percent yield = actual yield /theoretical yield x 100 %

Put value in the above formula

percent yield = 200 g/ 213 g x 100 %

percent yield = 94 %

So percent yield of H₂SO₄ = 94 %

8 0

3 years ago