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3 years ago

Which (3 of the 4) quantities must be conserved in all chemical reactions?

1 answer:

7 0

Mass, charge, and energy are conserved, no matter how much volume of
space they may be spread through either before or after the reaction.

Concerning density ...
Think about the fascinating classroom demonstration where the teacher
drops a tiny pellet of sodium into a glass of water. The sodium gets very
excited, and it skates and skitters around on the surface of the water,
faster and faster, and eventually it explodes. All the girls in the class
scream, while the guys are just sitting there and staring at the cloud
of steam that's rising from the glass of water. The whole point here
is that the density of the steam is much different from the density of
either the water or the sodium that reacted to create it. The density
is not conserved.

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What causes the earth’s magnetic field? A. currents in the earth’s liquid-metal outer core B. the mineral composition of the ear

S_A_V [24]

The magnetic field is believed to be generated by electric currents in the conductive material of its core, created by convection currents due to heat escaping from the core. So your answer is A

8 0

3 years ago

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Why is a homogeneous mixture not considered a pure substance? Question 6 options: A pure substance can be separated by physical

krok68 [10]

1. Why is a homogeneous mixture not considered a pure substance?

Answer:

A pure substance can be separated by chemical means, while a mixture can be separated by physical means.

2. What is true if mass is conserved in a reaction?

Answer:

There are equal numbers of atoms on both sides.

3. Methane reacts with oxygen then what are the products?

Answer:

carbon dioxide and water

4. Which one of the following is not a homogeneous mixture?

Answer:

vegetable soup

5. The substance is not uniform in appearance and each part of the mixture contains a combination of different ingredients in different ratios.

Answer:

heterogeneous mixtures

6. If a solution is saturated, which of these is true?

Answer:

More solvent can be dissolved

7. Which of these substances are molecules?

Answer:

All compounds are molecules but not all molecules are compounds. Molecular oxygen (O2) and molecular nitrogen (N2) are not compounds because each is composed of a single element. So correct option is 3 and 4.

8. What makes a solution a homogeneous mixture?

Answer:

It is uniform in composition.

9. When a solute is added to a solution, why does it remain homogeneous?

Answer:

The solute dissolves.

10. The chemical formula of glucose is C6H12O6, so it is classified as a(n)

Answer:

pure substance.

11. How many chlorine (Cl) atoms would be in 4 molecules of salt (4 NaCl)?

Answer:

12. In a solution of salt and water, which component is the solute?

Answer:

Salt

13. These substances are all H2O2, Li , NaCl , O2

Answer:

Pure Substances

14. If you have 5 grams of product after a chemical reaction, how many grams of reactants did you have at the start of the reaction?

Answer:

15. What is the difference between a compound and a mixture?

Answer:

A compound is a pure substance, but a mixture is not.

16. A firework exploding would be an example of a(n) ________.

Answer:

Exothermic reaction

17. If Lavoisier heated 100 grams of powdered mercuric oxide to produce 93 grams of liquid mercury, how much oxygen would be released?

Solution

2HgO ==> 2Hg + O2

Mass of HgO = 100 g

Molar mass of HgO = 216.59 g/mol

Moles = mass/molar mass = 0.46 moles

From balance chemcial equation

HgO : O2

2 = 1

0.46 = (1 × 0.46 ) ÷ 2 = 0.23 moles

mass of O2 = moles× molar mass = 0.23 × 32 = 7.36 g

18. Using the Law of Conservation of Matter, determine the number of grams of iron sulfide (FeS) that will be produced in this reaction.

Solution

12g Fe + 64g S → _____ g FeS

According to Law of Conservation of Matter, The total mass of reactant is equal to total mass of product , so the number of grams of iron sulfide (FeS) that will be produced in this reaction as follow.

12 + 64 = 76 g of FeS

Hope this Help.

3 0

3 years ago

Read 2 more answers

I need help use e picture that’s the question I’m stuck on pleassse

aniked [119]

Answer:

1.14 M

Explanation:

grams/molar mass = ans. / volume

317/110.98=2.86/2.50=1.14 M

- Hope that helps! Please let me know if you need further explanation.

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3 years ago

The first system of classification of organisms was developed by?

Margarita [4]

its the second one alright

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3 years ago

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What happens to energy from the sun that is neither reflected nor absorbed by the atmosphere

Valentin [98]

Energy from the sun that is neither reflected nor absorbed by the atmosphere passes through the atmosphere to the surface. The ozone layer absorbes most of the ultraviolet radiation, water vapor, and carbon dioxide absorbs infared radiation, clouds, dust, and other gases also absorb energy.

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3 years ago