A cual grupo pertenecen las tierras raras y los elementos representativos??

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:

4

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:

5

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

How many molecules are in 92.9 g of NaOH?

kirza4 [7]

2.3226678127494718

this number you could probably simplify to your own standards on your own.

5 0

3 years ago

What are three methods of measuring the volume of an object?

Anarel [89]

L×w×h=v
length times width times height equals volume
the order in which you multiply does not matter

5 0

3 years ago

Colder air tends to have _____.

iogann1982 [59]

Answer:

I believe the answer is D

Explanation:

C is not correct

8 0

3 years ago

Calculate the volume of one mole of a gas at 1.00 atm pressure and 0 °C.

N76 [4]

Answer:

Solution:-

The gas is in the standard temperature and pressure condition i.e. at S.T.P

Therefore,

V

i

=22.4dm

3

V

f

=?

As given that the expansion is isothermal and reversible

∴ΔU=0

Now from first law of thermodynamics,

ΔU=q+w

∵ΔU=0

∴q=–w

Given that the heat is absorbed.

∴q=1000cal

⇒w=−q=−1000cal

Now,

Work done in a reversible isothermal expansion is given by-

w=−nRTln(

V

i

V

f

)

Given:-

T=0℃=273K

n=1 mol

∴1000=−nRTln(

V

i

V

f

)

⇒1000=−1×2.303×2×273×log(

22.4

V

f

)

Explanation:

6 0

2 years ago

A cual grupo pertenecen las tierras raras y los elementos representativos??​

A cual grupo pertenecen las tierras raras y los elementos representativos??